docs: add debugging instructions (#22)

angular-schule/ngx-deploy-starter#22
by @dianjuar

Author: dianjuar

docs/README_contributors.md

@@ -6,6 +6,7 @@
   - [2. npm link](#2-npm-link)
   - [3. Adding to an Angular project -- ng add](#3-adding-to-an-angular-project----ng-add)
   - [4. Testing](#4-testing)
+  - [5. Debugging](#5-debugging)
 - [Testing the standalone CLI](#testing-the-standalone-cli)
 - [Publish to NPM](#publish-to-npm)
 
@@ -148,6 +149,25 @@ cd angular-cli-ghpages/src
 npm test
 ```
 
+### 5. Debugging
+
+To debug angular-cli-ghpages you need to:
+
+1. Place `debugger` statement, where you want your deployer stops.
+2. Follow the steps of [npm link](#2-npm-link) described here. compile, link and install linked in a local project
+3. Now, on the project that you linked the deployer, run it on debug mode using:
+
+   - | Normal Command               | Command on Debug Mode                                                           |
+     | :--------------------------- | :------------------------------------------------------------------------------ |
+     | `ng deploy`                  | `node --inspect-brk ./node_modules/@angular/cli/bin/ng deploy`                  |
+     | `ng add angular-cli-ghpages` | `node --inspect-brk ./node_modules/@angular/cli/bin/ng add angular-cli-ghpages` |
+
+4. Use your favorite [Inspector Client](https://nodejs.org/de/docs/guides/debugging-getting-started/#inspector-clients) to debug
+
+> This is the standard procedure to debug a NodeJs project. If you need more information you can read the official Docs of NodeJs to learn more about it.
+>
+> _https://nodejs.org/de/docs/guides/debugging-getting-started/_
+
 ## Testing the standalone CLI
 
 To quickly test the file `engine.ts` directly, the standalone mode is the best option.