Add disable autoplay preference and group related settings into a dedicated page (#3626)

* add autoplay preference

* group accessibility settings into a dedicated page

* fix gray background on web

* Put a11y first

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Co-authored-by: Dan Abramov <dan.abramov@gmail.com>

src/lib/routes/types.ts

@@ -35,6 +35,7 @@ export type CommonNavigatorParams = {
   PreferencesFollowingFeed: undefined
   PreferencesThreads: undefined
   PreferencesExternalEmbeds: undefined
+  AccessibilitySettings: undefined
   Search: {q?: string}
   Hashtag: {tag: string; author?: string}
 }