Deduplicate or reconcile Introduction and Terminology pages

[negz]

What's Missing?

https://docs.crossplane.io/v1.11/getting-started/introduction/
https://docs.crossplane.io/v1.11/concepts/terminology/

There's a lot of redundancy in these two pages. They define common Crossplane terms, but do so using different language. I think we should either deduplicate them or update them such that the terminology page is a more detailed version of the introduction page. The terminology page also has elements of "style guide" - it talks about how to use certain Crossplane terms. That should probably be moved into part of the docs contribution guide.

[negz]

This is something I'd like to work on - I'm strongly opinionated about the nuance of how our core concepts are communicated.

[plumbis]

Agreed, this is mainly due to time constraints with the reorg and release. I was trying to not delete things without proper review first.

I think we should remove Terminology and just have two things:

1. Intro covering the high level for people that are new
2. Thorough /concepts pages for each Crossplane kind. This would be the in-depth reference for that individual component.

[plumbis]

Fixed in #475