Whitespace change to test Trac/Gitolite.

This references #8121

Signed-off-by: Austin Seipp <aseipp@pobox.com>

README.md

 The Glasgow Haskell Compiler
 ============================
 
-This is the source tree for [GHC] [1], a compiler and interactive
+This is the source tree for [GHC][1], a compiler and interactive
 environment for the Haskell functional programming language.
 
-For more information, visit [GHC's web site] [1].
+For more information, visit [GHC's web site][1].
 
-Information for developers of GHC can be found on the [GHC Trac] [2].
+Information for developers of GHC can be found on the [GHC Trac][2].
 
 
 Getting the Source