Updating README.md [ci skip]
Updating README.md [ci skip]

Updating the global Rails README following work by @strzalek et al which extracted Action View to a separate gem, and also some other improvements.

Summary of changes:

* Reordered the paragraphs from View-Model-Controller to Model-Controller-View, based on how (IMHO) most people think about the structure and hierarchy of the framework and their code in it.
* Added references to ActionView's README in the _View_ paragraph
* Reworded the _Controller_ paragraph to briefly mentioned routing as handled by Action Dispatch, and that both Action Dispatch and Action Controller work together to form the request-handling Action Pack
* Removed paragraph saying Action Pack is coupled with Action View, as this is no longer the case
* Added brief references to Action Mailer and Active Support, since they are both major Rails components. Briefly mentioned in the _View_ paragraph that Action View is often used to generate the body of the email, in addition to the other typical of using to build a response body.

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