[NOTICE] Website now has a staging environment

[Chesnay Schepler]

Hello,

Just so more people are aware of it, I recently enabled a staging 
environment for the Flink Website.

You can push the rebuilt website to the asf-staging branch in flink-web, 
and the changes will be visible at https://flink.staged.apache.org shortly.

This has been documented at 
https://cwiki.apache.org/confluence/display/FLINK/Website.


Currently a Hugo-based version of the Website (FLINK-22922) can be seen 
in the staging environment.


Cheers