Update url_helper.rb, adjust link_to api doc
Update url_helper.rb, adjust link_to api doc

Removed references to `button` in the `link_to` `disable_with` api
description.

ngpestelos/rails,yasslab/railsguides.jp,printercu/rails,rafaelfranca/omg-rails,fabianoleittes/rails,pvalena/rails,tgxworld/rails,palkan/rails,vipulnsward/rails,voray/rails,kmayer/rails,Edouard-chin/rails,illacceptanything/illacceptanything,hanystudy/rails,fabianoleittes/rails,gavingmiller/rails,prathamesh-sonpatki/rails,iainbeeston/rails,rafaelfranca/omg-rails,ledestin/rails,mtsmfm/rails,travisofthenorth/rails,flanger001/rails,esparta/rails,mohitnatoo/rails,aditya-kapoor/rails,sealocal/rails,samphilipd/rails,BlakeWilliams/rails,mtsmfm/railstest,mohitnatoo/rails,samphilipd/rails,MSP-Greg/rails,repinel/rails,Spin42/rails,vipulnsward/rails,illacceptanything/illacceptanything,prathamesh-sonpatki/rails,EmmaB/rails-1,lcreid/rails,bradleypriest/rails,kmcphillips/rails,lcreid/rails,esparta/rails,illacceptanything/illacceptanything,riseshia/railsguides.kr,matrinox/rails,starknx/rails,yalab/rails,starknx/rails,fabianoleittes/rails,kirs/rails-1,mechanicles/rails,pvalena/rails,alecspopa/rails,bradleypriest/rails,gauravtiwari/rails,assain/rails,kenta-s/rails,shioyama/rails,xlymian/rails,tijwelch/rails,illacceptanything/illacceptanything,georgeclaghorn/rails,georgeclaghorn/rails,odedniv/rails,Erol/rails,stefanmb/rails,hanystudy/rails,yahonda/rails,Stellenticket/rails,esparta/rails,utilum/rails,rails/rails,matrinox/rails,untidy-hair/rails,repinel/rails,gfvcastro/rails,georgeclaghorn/rails,aditya-kapoor/rails,kamipo/rails,xlymian/rails,repinel/rails,MSP-Greg/rails,koic/rails,baerjam/rails,betesh/rails,illacceptanything/illacceptanything,untidy-hair/rails,mohitnatoo/rails,fabianoleittes/rails,yhirano55/rails,felipecvo/rails,illacceptanything/illacceptanything,notapatch/rails,pschambacher/rails,BlakeWilliams/rails,kddeisz/rails,riseshia/railsguides.kr,mathieujobin/reduced-rails-for-travis,lucasmazza/rails,Erol/rails,schuetzm/rails,shioyama/rails,ledestin/rails,jeremy/rails,yawboakye/rails,marklocklear/rails,mechanicles/rails,kenta-s/rails,EmmaB/rails-1,travisofthenorth/rails,illacceptanything/illacceptanything,yahonda/rails,brchristian/rails,mathieujobin/reduced-rails-for-travis,rossta/rails,lcreid/rails,baerjam/rails,arunagw/rails,richseviora/rails,ledestin/rails,tjschuck/rails,Vasfed/rails,rails/rails,yhirano55/rails,gauravtiwari/rails,bolek/rails,maicher/rails,matrinox/rails,maicher/rails,betesh/rails,yalab/rails,tjschuck/rails,pschambacher/rails,assain/rails,yasslab/railsguides.jp,sealocal/rails,ngpestelos/rails,arunagw/rails,mathieujobin/reduced-rails-for-travis,brchristian/rails,baerjam/rails,gavingmiller/rails,tgxworld/rails,Stellenticket/rails,rbhitchcock/rails,riseshia/railsguides.kr,kenta-s/rails,joonyou/rails,stefanmb/rails,kddeisz/rails,mtsmfm/rails,elfassy/rails,printercu/rails,marklocklear/rails,yasslab/railsguides.jp,notapatch/rails,kmcphillips/rails,felipecvo/rails,illacceptanything/illacceptanything,georgeclaghorn/rails,coreyward/rails,alecspopa/rails,bogdanvlviv/rails,palkan/rails,flanger001/rails,bogdanvlviv/rails,lucasmazza/rails,Sen-Zhang/rails,Erol/rails,odedniv/rails,rails/rails,sealocal/rails,yhirano55/rails,mijoharas/rails,stefanmb/rails,eileencodes/rails,ngpestelos/rails,vipulnsward/rails,illacceptanything/illacceptanything,pschambacher/rails,illacceptanything/illacceptanything,jeremy/rails,Sen-Zhang/rails,mtsmfm/railstest,yalab/rails,aditya-kapoor/rails,baerjam/rails,MSP-Greg/rails,BlakeWilliams/rails,gfvcastro/rails,yasslab/railsguides.jp,gcourtemanche/rails,deraru/rails,Edouard-chin/rails,mtsmfm/railstest,utilum/rails,illacceptanything/illacceptanything,Erol/rails,BlakeWilliams/rails,coreyward/rails,jeremy/rails,iainbeeston/rails,Vasfed/rails,xlymian/rails,marklocklear/rails,tjschuck/rails,gfvcastro/rails,lcreid/rails,betesh/rails,mechanicles/rails,flanger001/rails,odedniv/rails,utilum/rails,mtsmfm/rails,bolek/rails,Spin42/rails,tgxworld/rails,prathamesh-sonpatki/rails,yawboakye/rails,elfassy/rails,esparta/rails,ttanimichi/rails,hanystudy/rails,tijwelch/rails,Stellenticket/rails,Stellenticket/rails,utilum/rails,arunagw/rails,tijwelch/rails,rbhitchcock/rails,palkan/rails,flanger001/rails,mijoharas/rails,kddeisz/rails,maicher/rails,printercu/rails,koic/rails,Envek/rails,MSP-Greg/rails,tgxworld/rails,notapatch/rails,gfvcastro/rails,illacceptanything/illacceptanything,yahonda/rails,ttanimichi/rails,samphilipd/rails,Envek/rails,gavingmiller/rails,kmcphillips/rails,repinel/rails,mijoharas/rails,travisofthenorth/rails,pvalena/rails,palkan/rails,eileencodes/rails,voray/rails,prathamesh-sonpatki/rails,mohitnatoo/rails,yalab/rails,deraru/rails,joonyou/rails,kaspth/rails,elfassy/rails,iainbeeston/rails,kamipo/rails,illacceptanything/illacceptanything,kmcphillips/rails,alecspopa/rails,assain/rails,rafaelfranca/omg-rails,bogdanvlviv/rails,schuetzm/rails,travisofthenorth/rails,assain/rails,rossta/rails,koic/rails,gcourtemanche/rails,richseviora/rails,iainbeeston/rails,untidy-hair/rails,kddeisz/rails,notapatch/rails,deraru/rails,brchristian/rails,Envek/rails,gcourtemanche/rails,betesh/rails,bogdanvlviv/rails,schuetzm/rails,kmayer/rails,aditya-kapoor/rails,illacceptanything/illacceptanything,rails/rails,arunagw/rails,illacceptanything/illacceptanything,yawboakye/rails,voray/rails,EmmaB/rails-1,Sen-Zhang/rails,ttanimichi/rails,bradleypriest/rails,gauravtiwari/rails,eileencodes/rails,vipulnsward/rails,starknx/rails,rossta/rails,coreyward/rails,yhirano55/rails,deraru/rails,printercu/rails,Spin42/rails,pvalena/rails,richseviora/rails,eileencodes/rails,untidy-hair/rails,Edouard-chin/rails,yawboakye/rails,Vasfed/rails,shioyama/rails,Envek/rails,kirs/rails-1,riseshia/railsguides.kr,felipecvo/rails,Vasfed/rails,joonyou/rails,lucasmazza/rails,Edouard-chin/rails,schuetzm/rails,kirs/rails-1,yahonda/rails,jeremy/rails,kamipo/rails,kaspth/rails,shioyama/rails,rbhitchcock/rails,kaspth/rails,tjschuck/rails,bolek/rails,kmayer/rails,joonyou/rails,mechanicles/rails