Add ormolu fixer.

This commit adds a fixer for the Haskell language, ormolu
(https://github.com/tweag/ormolu).

Signed-off-by: David Wood <david@davidtw.co>

doc/ale-supported-languages-and-tools.txt

@@ -195,6 +195,7 @@ Notes:
   * `hie`
   * `hindent`
   * `hlint`
+  * `ormolu`
   * `stack-build`!!
   * `stack-ghc`
   * `stylish-haskell`