Improve documentation of additionalModuleSources option

Resolves #20

README.md

@@ -1,17 +1,30 @@
 # typedoc-plugin-mdn-links
 
-Adds support for linking references to global types like `HTMLElement`, `WebAssembly`, and `Date` to their documentation pages on MDN.
+Adds support for linking references to global types like `HTMLElement`,
+`WebAssembly`, and `Date` to their documentation pages on MDN.
 
-If you're explicitly referencing a type in a comment, you can use `{@link !HTMLElement}` to have it processed by this plugin.
+If you're explicitly referencing a type in a comment, you can use `{@link
+!HTMLElement}` to have it processed by this plugin.
 
-If you set `--logLevel Verbose`, it will print out when failing to resolve a symbol to a page on MDN. Pull requests to fix failed resolution are welcome!
+If you set `--logLevel Verbose`, it will print out when failing to resolve a
+symbol to a page on MDN. Pull requests to fix failed resolution are welcome!
 
 Supports TypeDoc 0.23.x, 0.24.x and 0.25.x
 
-| Option                  | Default | Description                                                                                |
-| ----------------------- | ------- | ------------------------------------------------------------------------------------------ |
-| resolveUtilityTypes     | `true`  | Resolve links to `Partial`, `Omit`, etc. to their documentation on the TypeScript website. |
-| additionalModuleSources | `false` | Specify additional node_modules to attempt to resolve links to MDN from.                   |
+## Options
+
+-   `resolveUtilityTypes`
+
+    Defaults to `true`. If set, will resolve links to `Partial`, `Omit`, etc. to
+    their documentation on the TypeScript website.
+
+-   `additionalModuleSources`
+
+    Defaults to `[]`. Specifies additional node_modules packages to attempt to
+    resolve links to MDN from. By default, resolves types declared in the
+    `typescript`, `@types/web`, and `@webgpu/types` packages. You should only
+    need to set this option if using an unusual type package to define globally
+    available types.
 
 ## Changelog