feat(pm/wiki): enable scary transclusion

Scary transclusion, so called because it's scarily inefficient and
might cause frightful differences between pages on different wikis due
to caching, is Probably Not That Bad and Might Actually Be Quite Useful
For Transcluding Stuff From Freshly Wiki Onto Starry Sky Wiki.

It's not that useful to have it enabled the other way around, since as
it'll cause permission errors anyway, but it also is unlikely to really
cause problems in a vacuum...

packetmix/systems/wiki/wiki.nix

···
         $wgMFEnableMobilePreferences = true;
         wfLoadSkin( 'MinervaNeue' );
 
+        $wgEnableScaryTranscluding = true;
+
         $wgEnableEditRecovery = true;
 
         $wgShowExceptionDetails = true;