Add missing READMEs & Update package.json in all RN packages (#37090)

Summary:
This diff adds _missing_ README files for all public RN packages.

#### Changes:
For all public RN packages:
- Add _Missing_ READMEs

Update package.json in all RN packages to add:
- Issues, Bugs urls
- Keywords and Homepage urls to respective pkgs

## Changelog:

[GENERAL][ADDED] - Add missing README files for all public RN packages.
[GENERAL][CHANGED] - Update package.json in all RN packages to add required fields.

Pull Request resolved: https://github.com/facebook/react-native/pull/37090

Test Plan: - `yarn lint && yarn flow && yarn test-ci` --> _should be green_

Reviewed By: cortinico

Differential Revision: D45390861

Pulled By: hoxyq

fbshipit-source-id: 524a92de56a7cb553573d9f54ccf40a998dfd35f