Deploy and manage -> Monitoring post migration initial cleaning

[eedugon]

• Front matter applies added to all docs
• Some files renamed to avoid confusion.
• 3 heroku documents migrated by mistake have been removed (mapped urls added to the right files).
• double overview solved by deleting one file

Still a lot of work to do but I'd like to start with this.

[shainaraskas]

probably dug in too deep here.

had a couple of questions about things that I wasn't sure applied to all deployment types, but as long as we validate them when we get to the refinement stage we should be ok

Couple of things to possibly address in this PR:

• the double overview
• marking features as GA before 9.x (not needed - just say "all")

approved to unblock, but if you make changes you'll need another quick ✅ so lmk if you need it from me

as a side note, this PR inspired me to open this feature request: elastic/docs-builder#420 :)

[shainaraskas]

probably dug in too deep here.

had a couple of questions about things that I wasn't sure applied to all deployment types, but as long as we validate them when we get to the refinement stage we should be ok

Couple of things to possibly address in this PR:

• the double overview
• marking features as GA before 9.x (not needed - just say "all")

approved to unblock, but if you make changes you'll need another quick ✅ so lmk if you need it from me

as a side note, this PR inspired me to open this feature request: elastic/docs-builder#420 :)