docs: remove solution style tsconfig (angular#38394)

Following the issues highlighted in
https://docs.google.com/document/d/1eB6cGCG_2ircfS5GzpDC9dBgikeYYcMxghVH5sDESHw/edit?usp=sharing
and discussions held with the TypeScript team.
Together with the TypeScript team it was decided that the best course of action is to rollback this feature.

In future, it is not excluded that solution style tsconfigs are re-introduced.

See: angular/angular-cli#18478

PR Close angular#38394

Author: alan-agius4

aio/content/guide/angular-compiler-options.md

@@ -31,7 +31,7 @@ For example:
 
 ```json
 {
-  "extends": "../tsconfig.base.json",
+  "extends": "../tsconfig.json",
   "compilerOptions": {
     "experimentalDecorators": true,
     ...

aio/content/guide/file-structure.md

@@ -40,8 +40,7 @@ The top level of the workspace contains workspace-wide configuration files, conf
 | `package-lock.json`     | Provides version information for all packages installed into `node_modules` by the npm client. See [npm documentation](https://docs.npmjs.com/files/package-lock.json) for details. If you use the yarn client, this file will be [yarn.lock](https://yarnpkg.com/lang/en/docs/yarn-lock/) instead. |
 | `src/`                  | Source files for the root-level application project. |
 | `node_modules/`         | Provides [npm packages](guide/npm-packages) to the entire workspace. Workspace-wide `node_modules` dependencies are visible to all projects. |
-| `tsconfig.json`         | The `tsconfig.json` file is a ["Solution Style"](https://www.typescriptlang.org/docs/handbook/release-notes/typescript-3-9.html#support-for-solution-style-tsconfigjson-files) TypeScript configuration file. Code editors and TypeScript’s language server use this file to improve development experience. Compilers do not use this file. |
-| `tsconfig.base.json`    | The base [TypeScript](https://www.typescriptlang.org/) configuration for projects in the workspace. All other configuration files inherit from this base file. For more information, see the [Configuration inheritance with extends](https://www.typescriptlang.org/docs/handbook/tsconfig-json.html#configuration-inheritance-with-extends) section of the TypeScript documentation.|
+| `tsconfig.json`         | The base [TypeScript](https://www.typescriptlang.org/) configuration for projects in the workspace. All other configuration files inherit from this base file. For more information, see the [Configuration inheritance with extends](https://www.typescriptlang.org/docs/handbook/tsconfig-json.html#configuration-inheritance-with-extends) section of the TypeScript documentation.|
 | `tslint.json`           | Default [TSLint](https://palantir.github.io/tslint/) configuration for projects in the workspace. |
 
 
@@ -103,7 +102,7 @@ Angular components, templates, and styles go here.
 The application-specific configuration files for the root application reside at the workspace root level.
 For a multi-project workspace, project-specific configuration files are in the project root, under `projects/project-name/`.
 
-Project-specific [TypeScript](https://www.typescriptlang.org/) configuration files inherit from the workspace-wide `tsconfig.base.json`, and project-specific [TSLint](https://palantir.github.io/tslint/) configuration files inherit from the workspace-wide `tslint.json`.
+Project-specific [TypeScript](https://www.typescriptlang.org/) configuration files inherit from the workspace-wide `tsconfig.json`, and project-specific [TSLint](https://palantir.github.io/tslint/) configuration files inherit from the workspace-wide `tslint.json`.
 
 | APPLICATION-SPECIFIC CONFIG FILES    | PURPOSE |
 | :--------------------- | :------------------------------------------|

aio/content/guide/ivy-compatibility.md

@@ -11,11 +11,11 @@ That said, some applications will likely need to apply some manual updates.
 In version 10, [a few deprecated APIs have been removed](guide/updating-to-version-10#removals) and there are a [few breaking changes](guide/updating-to-version-10#breaking-changes) unrelated to Ivy.
 If you're seeing errors after updating to version 9, you'll first want to rule those changes out.
 
-To do so, temporarily [turn off Ivy](guide/ivy#opting-out-of-angular-ivy) in your `tsconfig.base.json` and re-start your app.
+To do so, temporarily [turn off Ivy](guide/ivy#opting-out-of-angular-ivy) in your `tsconfig.json` and re-start your app.
 
 If you're still seeing the errors, they are not specific to Ivy. In this case, you may want to consult the [general version 10 guide](guide/updating-to-version-10). If you've opted into any of the new, stricter type-checking settings, you may also want to check out the [template type-checking guide](guide/template-typecheck).
 
-If the errors are gone, switch back to Ivy by removing the changes to the `tsconfig.base.json` and review the list of expected changes below.
+If the errors are gone, switch back to Ivy by removing the changes to the `tsconfig.json` and review the list of expected changes below.
 
 {@a payload-size-debugging}
 ### Payload size debugging

aio/content/guide/migration-solution-style-tsconfig.md

@@ -9,7 +9,7 @@ This process helps ensure that intentional changes to the options are kept in pl
 
 TypeScript Configuration File(s) | Changed Property | Existing Value | New Value
 ------------- | ------------- | ------------- | ------------- | -------------
-`<workspace base>/tsconfig.base.json` | `"module"` | `"esnext"` | `"es2020"`
+`<workspace base>/tsconfig.json` | `"module"` | `"esnext"` | `"es2020"`
 Used in `browser` builder options (`ng build` for applications) | `"module"` | `"esnext"` | `"es2020"`
 Used in `ng-packgr` builder options (`ng build` for libraries) | `"module"` | `"esnext"` | `"es2020"`
 Used in `karma` builder options (`ng test` for applications) | `"module"` | `"esnext"` | `"es2020"`

aio/content/guide/migration-update-module-and-target-compiler-options.md

@@ -18,32 +18,7 @@ that are important to Angular developers, including details about the following
 ## Configuration files
 
 A given Angular workspace contains several TypeScript configuration files.
-At the root level, there are two main TypeScript configuration files: a `tsconfig.json` file and a `tsconfig.base.json` file.
-
-The `tsconfig.json` file is a ["Solution Style"](https://www.typescriptlang.org/docs/handbook/release-notes/typescript-3-9.html#support-for-solution-style-tsconfigjson-files) TypeScript configuration file.
-Code editors and TypeScript’s language server use this file to improve development experience.
-Compilers do not use this file.
-
-The `tsconfig.json` file contains a list of paths to the other TypeScript configuration files used in the workspace.
-
-<code-example lang="json" header="tsconfig.json" linenums="false">
-{
- "files": [],
- "references": [
-   {
-     "path": "./tsconfig.app.json"
-   },
-   {
-     "path": "./tsconfig.spec.json"
-   },
-   {
-     "path": "./projects/my-lib/tsconfig.lib.json"
-   }
- ]
-}
-</code-example>
-
-The `tsconfig.base.json` file specifies the base TypeScript and Angular compiler options that all projects in the workspace inherit.
+At the root `tsconfig.json` file specifies the base TypeScript and Angular compiler options that all projects in the workspace inherit.
 
 The TypeScript and Angular have a wide range of options which can be used to configure type-checking features and generated output.
 For more information, see the [Configuration inheritance with extends](https://www.typescriptlang.org/docs/handbook/tsconfig-json.html#configuration-inheritance-with-extends) section of the TypeScript documentation.
@@ -55,9 +30,9 @@ For details about configuration inheritance, see the [Configuration inheritance
 
 </div>
 
-The initial `tsconfig.base.json` for an Angular workspace typically looks like the following example.
+The initial `tsconfig.json` for an Angular workspace typically looks like the following example.
 
-<code-example lang="json" header="tsconfig.base.json" linenums="false">
+<code-example lang="json" header="tsconfig.json" linenums="false">
 {
   "compileOnSave": false,
   "compilerOptions": {

aio/content/guide/typescript-configuration.md

@@ -48,8 +48,7 @@ src/
   app/ ...                   <i>application code</i>
     app.server.module.ts     <i>* server-side application module</i>
 server.ts                    <i>* express web server</i>
-tsconfig.json                <i>TypeScript solution style configuration</i>
-tsconfig.base.json           <i>TypeScript base configuration</i>
+tsconfig.json                <i>TypeScript base configuration</i>
 tsconfig.app.json            <i>TypeScript browser application configuration</i>
 tsconfig.server.json         <i>TypeScript server application configuration</i>
 tsconfig.spec.json           <i>TypeScript tests configuration</i>

aio/content/guide/universal.md

@@ -77,6 +77,5 @@ Read about the migrations the CLI handles for you automatically:
 
 * [Migrating missing `@Directive()`/`@Component()` decorators](guide/migration-undecorated-classes)
 * [Migrating `ModuleWithProviders`](guide/migration-module-with-providers)
-* [Solution-style `tsconfig.json` migration](guide/migration-solution-style-tsconfig)
 * [`tslib` direct dependency migration](guide/migration-update-libraries-tslib)
 * [Update `module` and `target` compiler options migration](guide/migration-update-module-and-target-compiler-options)

aio/content/guide/updating-to-version-10.md

@@ -858,11 +858,6 @@
                   "title": "Missing @Injectable() Decorators",
                   "tooltip": "Migration to add missing @Injectable() decorators and incomplete provider definitions."
                 },
-                {
-                  "url": "guide/migration-solution-style-tsconfig",
-                  "title": "Solution-style `tsconfig.json`",
-                  "tooltip": "Migration to create a solution-style `tsconfig.json`."
-                },
                 {
                   "url": "guide/migration-update-libraries-tslib",
                   "title": "`tslib` direct dependency",