feat(docs): describe `updateTemplates`

docs/3.api/4.advanced/2.kit.md

@@ -1960,7 +1960,69 @@ A template object or a string with the path to the template. If a string is prov
 
   A function that will be called with the `options` object. It should return a string or a promise that resolves to a string. If `src` is provided, this function will be ignored.
 
-### `updateTemplates({ filter?: ResolvedNuxtTemplate => boolean })`
+### `updateTemplates`
+
+Regenerate templates that match the filter. If no filter is provided, all templates will be regenerated.
+
+#### Type
+
+```ts
+async function updateTemplates (options: UpdateTemplatesOptions): void
+
+interface UpdateTemplatesOptions {
+  filter?: (template: ResolvedNuxtTemplate) => boolean
+}
+
+interface ResolvedNuxtTemplate {
+  src: string
+  filename: string
+  dst: string
+  options: Record<string, any>
+  getContents: (data: Record<string, any>) => string | Promise<string>
+  write: boolean
+  filename: string
+  dst: string
+}
+```
+
+#### Parameters
+
+##### `options`
+
+**Type**: `UpdateTemplatesOptions`
+
+**Default**: `{}`
+
+Options to pass to the template. This object can have the following property:
+
+- `filter` (optional)
+
+  **Type**: `(template: ResolvedNuxtTemplate) => boolean`
+
+  A function that will be called with the `template` object. It should return a boolean indicating whether the template should be regenerated. If `filter` is not provided, all templates will be regenerated.
+
+#### Example
+
+```ts
+// https://github.com/nuxt/nuxt
+import { defineNuxtModule, updateTemplates } from '@nuxt/kit'
+
+export default defineNuxtModule({
+  setup(options, nuxt) {
+    // watch and rebuild routes template list when one of the pages changes
+    nuxt.hook('builder:watch', async (event, relativePath) => {
+      if (event === 'change') { return }
+
+      const path = resolve(nuxt.options.srcDir, relativePath)
+      if (updateTemplatePaths.some(dir => path.startsWith(dir))) {
+        await updateTemplates({
+          filter: template => template.filename === 'routes.mjs'
+        })
+      }
+    })
+  }
+})
+```
 
 ## Nitro