docs: Add usage notes in readme

Author: pawamoy

README.md

@@ -14,3 +14,62 @@ Feedback is welcome.
 This project is available to sponsors only, through my Insiders program.
 See Insiders [explanation](https://mkdocstrings.github.io/typescript/insiders/)
 and [installation instructions](https://mkdocstrings.github.io/typescript/insiders/installation/).
+
+## Usage
+
+Add these [TypeDoc](https://typedoc.org/) configuration files to your repository:
+
+```tree hl_lines="4 5"
+./
+    src/
+        package1/
+    typedoc.base.json
+    typedoc.json
+```
+
+```json title="typedoc.base.json"
+{
+  "$schema": "https://typedoc.org/schema.json",
+  "includeVersion": true
+}
+```
+
+```json title="typedoc.json"
+{
+  "extends": ["./typedoc.base.json"],
+  "entryPointStrategy": "packages",
+  "entryPoints": ["./src/*"]
+}
+```
+
+Update the entrypoints to match your file layout so that TypeDoc can find your packages. See [TypeDoc's configuration documentation](https://typedoc.org/options/configuration/).
+
+Then in each of your package, add this TypeDoc configuration file:
+
+```tree hl_lines="4"
+./
+    src/
+        package1/
+            typedoc.json
+    typedoc.base.json
+    typedoc.json
+```
+
+```json title="typedoc.json"
+{
+  "extends": ["../../typedoc.base.json"],
+  "entryPointStrategy": "expand",
+  "entryPoints": ["src/index.d.ts"]
+}
+```
+
+Again, update entrypoints to match your file and package layout. See [TypeDoc's configuration documentation](https://typedoc.org/options/configuration/).
+
+**Your packages must be built for TypeDoc to work.**
+
+You are now able to use the TypeScript handler to inject API docs in your Markdown pages by referencing package names:
+
+```python
+::: @owner/packageName
+    handler: typescript
+```