Completed full edit

What does this MR do?

This MR goes through the Code Suggestions pages and streamlines/edits the information. I felt the docs were becoming cluttered and could be improved.

• I moved the 16.1 and 16.2 SM enable instructions to their own page, because it cluttered the page and some day we will get rid of that info. (Usually we don't include information about old versions, but I think it's OK in this case.)
• I moved the topic from the Groups page (the setting for enabling) and put it on the Code Suggestions SaaS page instead, so users don't have to jump back and forth.
• I put the "How to use Code Suggestions" information at the top of the SM and SaaS pages. Let's tell people how to use it, then we'll tell them how to enable.

Related issues

Author's checklist

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Reviewer's checklist

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