Improve documentation for controller how to get included helpers [ci skip]
Improve documentation for controller how to get included helpers [ci skip]

Closes #11671

tjschuck/rails,yasslab/railsguides.jp,kaspth/rails,gavingmiller/rails,matrinox/rails,ledestin/rails,Stellenticket/rails,yalab/rails,prathamesh-sonpatki/rails,MSP-Greg/rails,utilum/rails,jeremy/rails,gauravtiwari/rails,ngpestelos/rails,mtsmfm/rails,sealocal/rails,repinel/rails,sergey-alekseev/rails,betesh/rails,Vasfed/rails,travisofthenorth/rails,88rabbit/newRails,koic/rails,coreyward/rails,illacceptanything/illacceptanything,prathamesh-sonpatki/rails,mohitnatoo/rails,mathieujobin/reduced-rails-for-travis,yhirano55/rails,yawboakye/rails,tijwelch/rails,felipecvo/rails,lucasmazza/rails,jeremy/rails,bogdanvlviv/rails,travisofthenorth/rails,bradleypriest/rails,gavingmiller/rails,illacceptanything/illacceptanything,koic/rails,yasslab/railsguides.jp,pschambacher/rails,arjes/rails,kirs/rails-1,bogdanvlviv/rails,tgxworld/rails,lucasmazza/rails,georgeclaghorn/rails,Vasfed/rails,esparta/rails,tgxworld/rails,rafaelfranca/omg-rails,BlakeWilliams/rails,arunagw/rails,rails/rails,maicher/rails,yalab/rails,hanystudy/rails,mathieujobin/reduced-rails-for-travis,travisofthenorth/rails,tijwelch/rails,untidy-hair/rails,xlymian/rails,bolek/rails,untidy-hair/rails,mtsmfm/rails,kenta-s/rails,notapatch/rails,sergey-alekseev/rails,lucasmazza/rails,Spin42/rails,joonyou/rails,flanger001/rails,eileencodes/rails,marklocklear/rails,samphilipd/rails,baerjam/rails,aditya-kapoor/rails,kmcphillips/rails,Stellenticket/rails,shioyama/rails,shioyama/rails,illacceptanything/illacceptanything,alecspopa/rails,ttanimichi/rails,voray/rails,Spin42/rails,richseviora/rails,esparta/rails,pvalena/rails,georgeclaghorn/rails,Envek/rails,joonyou/rails,EmmaB/rails-1,88rabbit/newRails,gfvcastro/rails,rafaelfranca/omg-rails,matrinox/rails,rafaelfranca/omg-rails,kamipo/rails,lcreid/rails,lcreid/rails,kddeisz/rails,rbhitchcock/rails,vipulnsward/rails,Stellenticket/rails,amoody2108/TechForJustice,brchristian/rails,yasslab/railsguides.jp,Vasfed/rails,BlakeWilliams/rails,BlakeWilliams/rails,iainbeeston/rails,pschambacher/rails,bogdanvlviv/rails,EmmaB/rails-1,yawboakye/rails,ttanimichi/rails,Erol/rails,bradleypriest/rails,illacceptanything/illacceptanything,elfassy/rails,fabianoleittes/rails,ttanimichi/rails,utilum/rails,kmayer/rails,odedniv/rails,illacceptanything/illacceptanything,yalab/rails,assain/rails,yawboakye/rails,jeremy/rails,ledestin/rails,Edouard-chin/rails,kamipo/rails,printercu/rails,mtsmfm/railstest,Edouard-chin/rails,tjschuck/rails,gauravtiwari/rails,alecspopa/rails,starknx/rails,bolek/rails,matrinox/rails,mechanicles/rails,utilum/rails,kenta-s/rails,shioyama/rails,yhirano55/rails,illacceptanything/illacceptanything,gfvcastro/rails,illacceptanything/illacceptanything,deraru/rails,stefanmb/rails,illacceptanything/illacceptanything,MichaelSp/rails,mtsmfm/rails,eileencodes/rails,samphilipd/rails,arunagw/rails,Stellenticket/rails,betesh/rails,kamipo/rails,coreyward/rails,felipecvo/rails,kmcphillips/rails,yasslab/railsguides.jp,baerjam/rails,repinel/rails,kddeisz/rails,gauravtiwari/rails,88rabbit/newRails,kmayer/rails,aditya-kapoor/rails,prathamesh-sonpatki/rails,mathieujobin/reduced-rails-for-travis,samphilipd/rails,felipecvo/rails,yahonda/rails,kaspth/rails,mtsmfm/railstest,rails/rails,baerjam/rails,kirs/rails-1,fabianoleittes/rails,ledestin/rails,printercu/rails,illacceptanything/illacceptanything,rossta/rails,georgeclaghorn/rails,Vasfed/rails,maicher/rails,tjschuck/rails,mijoharas/rails,deraru/rails,untidy-hair/rails,hanystudy/rails,vassilevsky/rails,MichaelSp/rails,iainbeeston/rails,riseshia/railsguides.kr,voray/rails,utilum/rails,esparta/rails,mechanicles/rails,arjes/rails,alecspopa/rails,starknx/rails,richseviora/rails,sealocal/rails,georgeclaghorn/rails,schuetzm/rails,Sen-Zhang/rails,notapatch/rails,stefanmb/rails,rails/rails,mechanicles/rails,palkan/rails,joonyou/rails,vipulnsward/rails,arunagw/rails,kachick/rails,travisofthenorth/rails,xlymian/rails,lcreid/rails,eileencodes/rails,esparta/rails,kaspth/rails,prathamesh-sonpatki/rails,tgxworld/rails,mohitnatoo/rails,Erol/rails,illacceptanything/illacceptanything,vipulnsward/rails,mohitnatoo/rails,kirs/rails-1,hanystudy/rails,flanger001/rails,jeremy/rails,gcourtemanche/rails,brchristian/rails,illacceptanything/illacceptanything,odedniv/rails,bolek/rails,palkan/rails,pschambacher/rails,MSP-Greg/rails,rossta/rails,betesh/rails,yahonda/rails,rbhitchcock/rails,vipulnsward/rails,eileencodes/rails,riseshia/railsguides.kr,kmcphillips/rails,fabianoleittes/rails,aditya-kapoor/rails,vassilevsky/rails,repinel/rails,mijoharas/rails,ngpestelos/rails,gcourtemanche/rails,EmmaB/rails-1,amoody2108/TechForJustice,iainbeeston/rails,Erol/rails,tjschuck/rails,kddeisz/rails,sealocal/rails,untidy-hair/rails,mohitnatoo/rails,gcourtemanche/rails,yahonda/rails,rossta/rails,Envek/rails,coreyward/rails,gfvcastro/rails,fabianoleittes/rails,arjes/rails,starknx/rails,rails/rails,marklocklear/rails,joonyou/rails,Envek/rails,yalab/rails,xlymian/rails,riseshia/railsguides.kr,flanger001/rails,aditya-kapoor/rails,flanger001/rails,derar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