[CNCFSD-2427] KEDA Documentation improvements

[nate-double-u]

Follow up to CNCFSD-1008, #87

CNCF TechDocs team to help KEDA with documentation improvements project.

Proposed CNCF Scope: KEDA Documentation Improvements - CNCF Plan. This can be altered and updated if other issues become a priority, but initially we think this is what we can help with. Work is active and ongoing.