Increase Example List Density (#46080)

Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/46080

1. Force the examples to be alphabetized, where the hand-maintained list has some examples that are not
2. Remove reundant/not useful UI

Changelog: [Internal]

Reviewed By: cortinico

Differential Revision: D61430910

fbshipit-source-id: 1f3e116fe81502faa7a72f2720912e26c9f04bb2