doc: Merged old docs for Hash#merge, updated example.
doc: Merged old docs for Hash#merge, updated example.

erpframework/prototype,ldf7801528/prototype,erpframework/prototype,erpframework/prototype,lamsieuquay/prototype,ShefronYudy/prototype,ShefronYudy/prototype,Jiasm/prototype,ldf7801528/prototype,sstephenson/prototype,ridixcr/prototype,lamsieuquay/prototype,baiyanghese/prototype,ridixcr/prototype,Jiasm/prototype,Gargaj/prototype,loduis/prototype,baiyanghese/prototype,sstephenson/prototype,sdumitriu/prototype,Gargaj/prototype,leafo/prototype,sdumitriu/prototype,loduis/prototype,292388900/prototype,loduis/prototype,292388900/prototype,ridixcr/prototype,lamsieuquay/prototype,fashionsun/prototype,Jiasm/prototype,sstephenson/prototype,fashionsun/prototype,fashionsun/prototype,sdumitriu/prototype,292388900/prototype,leafo/prototype,Gargaj/prototype,ShefronYudy/prototype,ldf7801528/prototype