[DOCS]: Add details about the various use cases for the packages published to NPM via this repo

[nickfloyd]

Describe the need

There are questions that come up occasionally about "missing" types when the actual issue is that the consumer needs to use the corresponding platform package - i.e. GHAE, GHES, + all of the corresponding versions.

This behavior is opaque to new users because it requires understanding the various aspects of the GitHub platform and how that translates to the Octokit JS environment.

SDK Version

No response

API Version

No response

Relevant log output

No response

Code of Conduct

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