Crosslink details about variables

What does this MR do?

We have information in the variable details that needs to be clear in the reference doc. This adds a note to each keyword that supports variables, with a link to the page that explains the variable expansion details. I'm also adding crosslinks from that other page to link back to the specific keywords themselves, for easy reference. This way we can maintain the SSoT in the single page, and simply link to it when needed.

Related issues

• Resolves #345123 (closed)
• Related to !88867 (closed)

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