Title: Docs for recent tags show pre-release banner

Description:
All recent tags after https://www.envoyproxy.io/docs/envoy/v1.16.0/ appears to now show the pre-release banner, which I believe previously was only there for https://www.envoyproxy.io/docs/envoy/latest/. Not sure about the correctness of the actual docs in relation to the tag, or if it is only the banner that is incorrectly rendered.