Added SanitizeHelper to rails guide docs [ci skip]

Added SanitizeHelper to rails guide docs [ci skip]

Added SanitizeHelper to rails guide docs update [ci skip]
added String#to_date documentation to Rails 4 upgrade guide

[ci skip]
 #11804: Add description of action in Getting Started Guide

[ci skip]

Closes #11804
Updated outdated initialization guide [ci skip]
Add String#remove(pattern) as a short-hand for the common pattern of String#gsub(pattern, '')
Merge pull request #11847 from AJ-Acevedo/master

Updated outdated initialization guide [ci skip]
Merge pull request #11807 from jetthoughts/11804_actions_are_public_methods

Add description of action in Getting Started Guide [ci skip]
Generate namespaced routes correctly for generators. Fix for #11532
Merge pull request #11756 from zilkey/master

added String#to_date documentation to Rails 4 upgrade guide [ci skip]
test-case for fixed issue #11870.
Merge pull request #11544 from prathamesh-sonpatki/namespaced_routes_test

Generate namespaced routes correctly for generators. Fix for #11532
Merge pull request #11617 from swooop/doc_sanitize

Added SanitizeHelper to rails guide docs [ci skip]
document `assert_not_XYZ` in place of `refute_XYZ`.
Rescue invalid ip address exceptions on assign.

In order that set attribute should not be bang method