Update TOC
Download latest translation files from GTT
Publish 'Rails ルーティング' translated by @hachi8833
Close #6: typo in getting_started.md
Fix #8: typo in security.md
[WIP] Update 'レイアウトとレンダリング' to the latest translation by @hachi8833
Remove git conflicts on GTT
Fix wrong indents and typos in Testing
Apply updated TOC to all chapters