Removed params permit step from 5.6 section [ci skip]
Removed redundant upgrade docs on new cookies.

[ci skip]
Merge pull request #11261 from ryan-endacott/fixguide

Removed redundant upgrade docs on new cookies.
Replaced older rocket sign to new :
Merge pull request #11295 from ankit8898/master

Replaced older rocket sign to new  ":"
SQL Keywords to be in UPPERCASE
Merge pull request #11297 from ankit8898/master

SQL keywords in UPPERCASE
Removed unsued deprecation require
Remove deprecated `ActiveRecord::Base.disable_implicit_join_references=`.
Removed deprecated `Rails.application.railties.engines`.
Merge pull request #11300 from arunagw/railties-engine-deprecation-removed

Removed deprecated `Rails.application.railties.engines`.
Merge pull request #11298 from raysrashmi/removed-deprecation-require

Removed unsued deprecation require
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]
Specify request method in guides [ci skip]
Merge pull request #11303 from evsyukovmv/specify-request-method-in-guides

Specify request method in guides [ci skip]
Cleanup belongs to tests

simplified logic to calculate number of queries by using assert_queries
removed markdown code markers which were rendering in the generated AR querying guide
Merge pull request #11309 from crakalakin/AR-querying-guide

removes markdown code markers from displaying in the active record querying guide [ci skip]