[RFC] Improve peer dependency handling

[reiv]

Currently the package pulls in dependencies which might not always be required (e.g. React). This makes the setup very easy right now but could bloat in the future.

Approach 1:

• Mark dependencies like eslint-plugin-react as peer dependencies
• Mark peer dependencies as optional if they aren't strictly required in all cases
• Install peer dependencies as part of the setup script (depending on the presets used)
• No monorepo required
• Plugins leak into the project's package.json (like in the old days)

Approach 2:

• Split up into separate packages with (non-peer) dependencies (e.g. linting-preset-react)
• Setup script assembles these packages
• Monorepo
• Plugins remain encapsulated

I think the second approach would also benefit projects which are themselves monorepos (microfrontends anyone?). But versioning everything might become a bit of a pain point.

[mvarendorff]

My gutfeeling says going with approach 2 is the long-term sane approach. For versioning, we could use changesets which I am already using to version the codegen-plugins. They also have a GitHub action we can just throw at the whole thing to auto-detect changesets and take charge on updating changelogs and versioning everything.

I am also unsure if the effort is really necessary at this time because the plugins are relatively small and don't contribute too much bloat to the node_modules compared to other packages ususally present in the project but I might be mistaken.