Extend version ranges of aeson and tasty-unit

these are reported as working by Simon Peters
arbtt.xml: fix duplicate ID in release notes
arbtt.xml: delete trailing whitespace
arbtt.xml: add self to doc authors, add a list of similar projects to intro to describe arbtt better
example categorize.cfg: add local variable to set emacs to haskell-mode
by adding the metadata, emacs users copying the example config get appropriate
syntax highlighting without additional work, and other users are reminded that
their favorite editor's haskell mode would work well in displaying arbtt configs
Put new text into a para