doc: add find import usage

fix #636

Author: HerringtonDarkholme

website/catalog/index.md

@@ -37,6 +37,7 @@ Feel free to join our [Discord](https://discord.gg/4YZjf6htSQ) channel and ask @
   * [No `console` except in `catch` block](/catalog/typescript/#no-console-except-in-catch-block)
   * [Find Import File without Extension](/catalog/typescript/#find-import-file-without-extension)
   * [Migrate XState to V5 from V4](/catalog/typescript/#migrate-xstate-to-v5-from-v4)
+  * [Find Import Usage](/catalog/typescript/#find-import-usage)
 * [TSX](/catalog/tsx/)
   * [Avoid `&&` short circuit in JSX](/catalog/tsx/#avoid-short-circuit-in-jsx)
   * [Rewrite MobX Component Style](/catalog/tsx/#rewrite-mobx-component-style)

website/catalog/typescript/find-import-usage.md

@@ -0,0 +1,46 @@
+## Find Import Usage
+
+* [Playground Link](/playground.html#eyJtb2RlIjoiQ29uZmlnIiwibGFuZyI6InR5cGVzY3JpcHQiLCJxdWVyeSI6IiIsInJld3JpdGUiOiIiLCJzdHJpY3RuZXNzIjoicmVsYXhlZCIsInNlbGVjdG9yIjoiIiwiY29uZmlnIjoicnVsZTpcbiAgIyB0aGUgdXNhZ2VcbiAga2luZDogaWRlbnRpZmllclxuICBwYXR0ZXJuOiAkTU9EXG4gICMgaXRzIHJlbGF0aW9uc2hpcCB0byB0aGUgcm9vdFxuICBpbnNpZGU6XG4gICAgc3RvcEJ5OiBlbmRcbiAgICBraW5kOiBwcm9ncmFtXG4gICAgIyBhbmQgYmFjayBkb3duIHRvIHRoZSBpbXBvcnQgc3RhdGVtZW50XG4gICAgaGFzOlxuICAgICAga2luZDogaW1wb3J0X3N0YXRlbWVudFxuICAgICAgIyBhbmQgZGVlcGVyIGludG8gdGhlIGltcG9ydCBzdGF0ZW1lbnQgbG9va2luZyBmb3IgdGhlIG1hdGNoaW5nIGlkZW50aWZpZXJcbiAgICAgIGhhczpcbiAgICAgICAgc3RvcEJ5OiBlbmRcbiAgICAgICAga2luZDogaW1wb3J0X3NwZWNpZmllclxuICAgICAgICBwYXR0ZXJuOiAkTU9EICMgc2FtZSBwYXR0ZXJuIGFzIHRoZSB1c2FnZSBpcyBlbmZvcmNlZCBoZXJlIiwic291cmNlIjoiaW1wb3J0IHsgTW9uZ29DbGllbnQgfSBmcm9tICdtb25nb2RiJztcbmNvbnN0IHVybCA9ICdtb25nb2RiOi8vbG9jYWxob3N0OjI3MDE3JztcbmFzeW5jIGZ1bmN0aW9uIHJ1bigpIHtcbiAgY29uc3QgY2xpZW50ID0gbmV3IE1vbmdvQ2xpZW50KHVybCk7XG59XG4ifQ==)
+
+### Description
+
+It is common to find the usage of an imported module in a codebase. This rule helps you to find the usage of an imported module in your codebase.
+The idea of this rule can be broken into several parts:
+
+* Find the use of an identifier `$MOD`
+* To find the import, we first need to find the root file of which `$MOD` is  `inside`
+* The `program` file `has` an `import` statement
+* The `import` statement `has` the identifier `$MOD`
+
+<!-- Use YAML in the example. Delete this section if use pattern. -->
+### YAML
+```yaml
+id: find-import-usage
+language: typescript
+rule:
+  kind: identifier # ast-grep requires a kind
+  pattern: $MOD   # the identifier to find
+  inside: # find the root
+    stopBy: end
+    kind: program
+    has: # and has the import statement
+      kind: import_statement
+      has: # look for the matching identifier
+        stopBy: end
+        kind: import_specifier
+        pattern: $MOD # same pattern as the usage is enforced here
+```
+
+### Example
+
+<!-- highlight matched code in curly-brace {lineNum} -->
+```ts {4}
+import { MongoClient } from 'mongodb';
+const url = 'mongodb://localhost:27017';
+async function run() {
+  const client = new MongoClient(url);
+}
+```
+
+### Contributed by
+[Steven Love](https://github.com/StevenLove)

website/catalog/typescript/index.md

@@ -13,4 +13,5 @@ However, you can use the [`languageGlobs`](/reference/sgconfig.html#languageglob
 <!--@include: ./find-import-file-without-extension.md-->
 <!--@include: ./migrate-xstate-v5.md-->
 <!--@include: ./no-await-in-promise-all.md-->
-<!--@include: ./no-console-except-catch.md-->
+<!--@include: ./no-console-except-catch.md-->
+<!--@include: ./find-import-usage.md-->