doc: merge old docs for Enumerable#detect, add example
doc: merge old docs for Enumerable#detect, add example

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