Remove deprecated `ActiveRecord::Base.disable_implicit_join_references=`.
Merge pull request #11299 from arunagw/disable_implicit_join_references_removed

Remove deprecated `ActiveRecord::Base.disable_implicit_join_references=`
Added link to Form Helper article from getting strated [ci skip]
Merge pull request #11187 from jetthoughts/form_for_explonation_in_getting_started

Added link to Form Helper article from getting strated [ci skip]
Correctly handle relations as values in where() for polymorphic associations.