* doc/contributing.rdoc: [DOC] Add notes about deciding what to patch


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@43899 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
* doc/contributing.rdoc: [DOC] Add coding style heading for patch
  rules


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@43900 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
* doc/contributing.rdoc: [DOC] Add heading above ChangeLog tips to
  setup entry for commits, its not required. Actually easier if
  contributors don't include a ChangeLog entry.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@43901 b2dd03c8-39d4-4d8f-98ff-823fe69b080e