system arch guide docs - update gear directories
Make READMEs in template repos more obvious

https://trello.com/c/dKJfwLdh - origin_cartridge_170

Also, remove unnecessary .gitkeep files and replace duplicated
'ruby/versions/{1.8,1.9}/template/.openshift/*' files with
directory symlink to 'ruby/versions/shared/template/.openshift/'.
Merge pull request #5451 from VojtechVitek/improve_template_repo_readmes

Merged by openshift-bot