Move Atom/Lens-only version to focal-atom

[oleksiilevzhynskyi]

Context

The Focal project ties together the state management logic and API for React integration. However, in some cases, React integration is redundant and brings uneccesarry dependencies to the project.

Well, the goal is to move the state management in a separate package to use it in non-React applications.

Implementation details

Overall, It's a second attempt to move Atom/Lens-only version into a separate package.

This MR split focal into two packages:

• @grammarly/focal-atom - contains only atoms/lenses-related code, without any dependency on React.
• @grammarly/focal keeps the same interface but depends on @focal-atom - no breaking changes here.

Limitations:

• to simplify version management, both packages release under the same version (https://github.com/facebook/react/releases releasing this way)
• to avoid cracking changes packages @grammarly/focal has a explicit dependency on @grammarly/focal-atom (^0.9.0)

Resolves #68

[KatSick]

I have no feedback to provide at this time. However, we should consider testing new packages with alpha versions before fully releasing them.

[oleksiilevzhynskyi]

@KatSick thank you! I'm going to bump the minor version and publish it as alpha - 0.10.0-alpha