Backport of docs: KV tutorial becomes usage doc into release/1.15.x#20995

hc-github-team-consul-core wants to merge 2 commits intorelease/1.15.xhashicorp/consul:release/1.15.xfrom

backport/docs/tutorial-refresh-support/mostly-settled-alienhashicorp/consul:backport/docs/tutorial-refresh-support/mostly-settled-alienCopy head branch name to clipboard