write README

README.md

-# haskell-wiki-bugs
-Issue tracking for Haskell Wiki
+No code here; this repository exists solely for [issue tracking][1].
+
+This issue tracker is for bugs and feature requests for the
+[Haskell Wiki][2].  This is just for issues with the
+installation/maintenance of the wiki software itself (which is an
+installation of [MediaWiki][3]).  For issues with the *content* of the
+wiki, just edit the wiki! 😃
+
+[1]: https://github.com/ppelleti/haskell-wiki-bugs/issues
+[2]: https://wiki.haskell.org/
+[3]: https://www.mediawiki.org/