Update installation.rst

Wrong (old?) link for SonatajQueryBundle installation instructions
Some incorrect comments

Fixed-up some incorrect comments that were copied over.
Another typo.

Another typo
Merge pull request #2007 from ConneXNL/patch-2

Some incorrect comments
Merge pull request #2005 from kdkwiatkow/patch-1

Update installation.rst
Added CONTRIBUTING.md file
Merge pull request #2008 from Bladrak/contributing

Added CONTRIBUTING.md file
Update action_show.rst

tiny grammer fix
Merge pull request #2010 from justinpfister/patch-1

Update action_show.rst
Update action_show.rst

updated the path to the default file
Merge pull request #2011 from justinpfister/patch-2

Update action_show.rst
Merge remote-tracking branch 'refs/remotes/sonata-project/master'