Fixing typo in README.md

Developmnent → Development
Merge pull request #37 from dereckson/patch-1

Fixing typo in README.md
Update README with disable_asset_compilation marker
Merge pull request #38 from jhadvig/readme_update

Update README with disable_asset_compilation marker
Add more groups into Gemfile
Merge pull request #39 from mfojtik/gemfile_groups

Add more groups into Gemfile
Helllooo
os
removed index
updated separator