SSL Reverse Proxy documentation for Apache

[tmortagne]

@TomTheWise

For realtime editing to work, the ProxyPass config line has to be expanded with " upgrade=websockets"
example: ProxyPass /xwiki http://localhost:8080/xwiki nocanon upgrade=websocket

Indeed, good point. It’s not something that was experimented much on xwiki.org yet, and it’s not really my area of expertise so putting your suggestion as is for now.