docs(preset-icon): complete options introduce (#3786)

Co-authored-by: Anthony Fu <anthonyfu117@hotmail.com>

docs/components.d.ts

@@ -1,10 +1,10 @@
 /* eslint-disable */
-/* prettier-ignore */
 // @ts-nocheck
 // Generated by unplugin-vue-components
 // Read more: https://github.com/vuejs/core/pull/3399
 export {}
 
+/* prettier-ignore */
 declare module 'vue' {
   export interface GlobalComponents {
     ContentExample: typeof import('./.vitepress/theme/components/ContentExample.vue')['default']

docs/presets/icons.md

@@ -482,7 +482,30 @@ Recommends:
 - `https://esm.sh/`
 - `https://cdn.skypack.dev/`
 
-### Advanced Custom Icon Set Cleanup
+### customFetch
+
+- Type: `(url: string) => Promise<any>`
+- Default: `undefined`
+
+Preset used [`ofetch`](https://github.com/unjs/ofetch) as the default fetcher, you can also custom fetch function to provide the icon data.
+
+### processor
+
+- Type: `(cssObject: CSSObject, meta: Required<IconMeta>) => void`
+- Default: `undefined`
+
+```ts
+interface IconMeta {
+  collection: string
+  icon: string
+  svg: string
+  mode?: IconsOptions['mode']
+}
+```
+
+Processor for the CSS object before stringify. See [example](https://github.com/unocss/unocss/blob/7d83789b0dee8c72c401db24263ea429086de95d/test/preset-icons.test.ts#L66-L82).
+
+## Advanced Custom Icon Set Cleanup
 
 When using this preset with your custom icons, consider using a cleanup process similar to that done by [Iconify](https://iconify.design/) for any icons sets. All the tools you need are available in [Iconify Tools](https://iconify.design/docs/libraries/tools/).