Backport of added an intro statement for the SI conf entry confiration model into release/1.15.x#17018

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

backport/docs/add-intro-svc-ints-conf-model/enormously-coherent-oxhashicorp/consul:backport/docs/add-intro-svc-ints-conf-model/enormously-coherent-oxCopy head branch name to clipboard