Update Installation (ko)
Improve summary of the "Installers" section (ko)

* ref 24c27d2
Link to installation page from quickstart page (ko)

* ref c774ec1
Update Documentation (ko)
Add books link, Remove miss inputed lines (ko)
Translate 2014-11-25-ruby-2-2-0-preview2-released [vi]
Fix links and spacing (ko)
Merge pull request #916 from ruby-vietnam/translate-ruby-2-2-pr2

Translate 2014-11-25-ruby-2-2-0-preview2-released [vi]
Fix missing punctuation; rewrap (vi)
Merge pull request #913 from marocchino/ko-install

Update Installation (ko)
Remove links to pik from installation page

pik has been unmaintained for some time.
Remove links to pik from downloads page (de,en,it,ja,ko,pl)
Add uru to Ruby managers (en)