Emphasis that bi-directional XDCR and SGR is unsupported

Could we further emphasise that bi-directional XDCR and Sync Gateway are unsupported and that it will cause issues?

There has been work to address this before, however it's still not too difficult to miss and some of our users do miss it

Could we add something akin to a box at the top possibly in red on a few key pages?

Pages like:
https://docs.couchbase.com/sync-gateway/current/sync-with-couchbase-server.html
https://docs.couchbase.com/sync-gateway/current/server-compatibility-xdcr.html

and possibly https://docs.couchbase.com/sync-gateway/current/configuration-overview.html