document common mime types

Author: vonovak

README.md

@@ -36,7 +36,7 @@ Use `pick` or `pickMultiple` to open a document picker for the user to select fi
 ##### `type`:`string|Array<string>`:
 
 The type or types of documents to allow selection of. May be an array of types as single type string.
-  - On Android these are MIME types such as `text/plain` or partial MIME types such as `image/*`.
+  - On Android these are MIME types such as `text/plain` or partial MIME types such as `image/*`. See [common MIME types](https://developer.mozilla.org/en-US/docs/Web/HTTP/Basics_of_HTTP/MIME_types/Common_types).
   - On iOS these must be Apple "[Uniform Type Identifiers](https://developer.apple.com/library/content/documentation/Miscellaneous/Reference/UTIRef/Articles/System-DeclaredUniformTypeIdentifiers.html)"
   - If `type` is omitted it will be treated as `*/*` or `public.content`.
   - Multiple type strings are not supported on Android before KitKat (API level 19), Jellybean will fall back to `*/*` if you provide an array with more than one value.