docs(no-goto-without-base): documented the rule

Author: marekdedic

docs/rules/no-goto-without-base.md

@@ -0,0 +1,63 @@
+---
+pageClass: 'rule-details'
+sidebarDepth: 0
+title: 'svelte/no-goto-without-base'
+description: 'disallow using goto() without the base path'
+---
+
+# svelte/no-goto-without-base
+
+> disallow using goto() without the base path
+
+- :exclamation: <badge text="This rule has not been released yet." vertical="middle" type="error"> **_This rule has not been released yet._** </badge>
+
+## :book: Rule Details
+
+This rule reports navigation using SvelteKit's `goto()` function without prefixing a relative URL with the base path. If a non-prefixed relative URL is used for navigation, the `goto` function navigates away from the base path, which is usually not what you wanted to do (for external URLs, `window.location = url` should be used instead).
+
+<ESLintCodeBlock>
+
+<!--eslint-skip-->
+
+```svelte
+<script>
+  /* eslint svelte/no-goto-without-base: "error" */
+
+  import { goto } from '$app/navigation';
+  import { base } from '$app/paths';
+  import { base as baseAlias } from '$app/paths';
+
+  // ✓ GOOD
+  goto(base + '/foo/');
+  goto(`${base}/foo/`);
+
+  goto(baseAlias + '/foo/');
+  goto(`${baseAlias}/foo/`);
+
+  goto('https://localhost/foo/');
+
+  // ✗ BAD
+  goto('/foo');
+
+  goto('/foo/' + base);
+  goto(`/foo/${base}`);
+</script>
+
+
+```
+
+</ESLintCodeBlock>
+
+## :wrench: Options
+
+Nothing.
+
+## :books: Further Reading
+
+- [`goto()` documentation](https://kit.svelte.dev/docs/modules#$app-navigation-goto)
+- [`base` documentation](https://kit.svelte.dev/docs/modules#$app-paths-base)
+
+## :mag: Implementation
+
+- [Rule source](https://github.com/sveltejs/eslint-plugin-svelte/blob/main/src/rules/no-goto-without-base.ts)
+- [Test source](https://github.com/sveltejs/eslint-plugin-svelte/blob/main/tests/src/rules/no-goto-without-base.ts)