Temporarily suspend Nearby pages beta feature

I think the initial run of this beta feature was extremely useful
but little value is now coming out for its development and it is
not actively maintained.

Next step:
https://www.mediawiki.org/wiki/Beta_Features/Nearby_Pages/Design
by @Prtksxna

Change-Id: I252ee73c562e637d3df45d0f93a124c8ae78b0a8
Merge "Temporarily suspend Nearby pages beta feature"