Corrected link to the Grails documentation

[egion]

The link to the Grails documentation led to a 404. I believe the page identified by http://docs.grails.org/latest/guide/theWebLayer.html#automaticLinkRewriting is the one that readers shall be forwarded to.

[ZacharyKlein]

@egion Apologies for the very long delay! It appears this PR failed to build due to missing Git identity information - if you can get that setup and try again I think we can get this merged.

*** Please tell me who you are.
Run
  git config --global user.email "[email protected]"
  git config --global user.name "Your Name"
to set your account's default identity.
Omit --global to set the identity only in this repository.
fatal: empty ident name (for <>) not allowed