Backport of adding redirects for tproxy and envoy extensions into release/1.16.x#17690

trujillo-adam merged 2 commits intorelease/1.16.xhashicorp/consul:release/1.16.xfrom

backport/docs/redirects-1.16-tproxy-envoy-ext/rightly-moral-pigeonhashicorp/consul:backport/docs/redirects-1.16-tproxy-envoy-ext/rightly-moral-pigeonCopy head branch name to clipboard