Convert User Guide from DocBook to AsciiDoc
See initial proposal and discussion on the mailing list: https://mail.haskell.org/pipermail/ghc-devs/2014-October/006599.html
and the more recent call for volunteers: https://ghc.haskell.org/trac/ghc/blog/weekly20150414
Quoting the latter: the idea [is] that it will A) make life easier for people who frequently modify the users guide, and B) make life easier for people who add things irregularly, as a lower barrier to entry.
I expect that asciidoc & DocBook can coexist while I work on this. After the initial changes to the build system, the docbook-to-HTML phase should read both the asciidoc-generated XML and the not-yet-converted XML files.
This ticket will track progress on the task, as I plan to submit multiple patches, perhaps as many as one per file converted.