Add better documentation for which WordPress versions are supported

[fabiankaegy]

Currently there is no way for a user of the library to know what WordPress version supports the various components. And this actually is a bit of a tricky issue to solve for because we don't bundle the @wordpress/ packages but instead rely on the dependency-extraction-webpack-plugin to use the already bundled version of those packages from core.

Because of this we can run into issues with which WordPress version actually supports a given component / props of those components.

It would be ideal to find a way to tie the WordPress support into the semantic versioning of the package so you can confidently use the package on the correct WordPress version without an auto update of the package breaking support with an older WordPress version.