* Link Compound's `TypographyTokens` to `ElementTheme`.
Also add some docs about when we should use each set of tokens.
* Renamed `LocalColors` to `LocalLegacyColors`.
Made both `LocalLegacyColors` and `LocalCompoundColors` internal. This means it will need to always be used through `ElementTheme.`
Also, removed any usages of `LocalColors.current` accross the project, they're now used through `ElementTheme.legacyColors`.