Docs: Create a glossary of common terms

[michaelryanpeter]

User story

I want a single source to find definitions and examples of common terms used in the OLM v1 docs. For example, what is the difference between an Operator and a cluster extension?

This doc would live in the References folder. I recommend using the definition list format that we can use for the MKDocs Material theme. https://squidfunk.github.io/mkdocs-material/reference/lists/#using-definition-lists

New content or update?

Net-new content

Types of documentation

Reference