Summary:
**Highlights**
- Changed to the upstream `adbkit` instead of the Facebook-specific fork of it.
- Migrate the rest of Flipper core from Flow to (strict) TypeScript.
- UI docs use the TypeScript code as basis.
Reviewed By: danielbuechele
Differential Revision: D17368399
fbshipit-source-id: 5ba92c4f0d4ca627ffac58052ef6e4d9fd07bd95
29c9379ae6