Refactored OptionsResolver docs to have a better example
Added cookbook page about sessions directory.
The instructions are incomplete.

Added routes and doctrine commands
removed duplicate timestamp limitation notice
added timestamp limitation notice for datetime
Added note about setting the label to false
Updated doc for the new way to render partials
Adding a section to outline the exact process the documentation team takes during the release lifecycle
[#2720] Tweaks thanks to @WouterJ
Removed trailing whitespace
Deleted blank lines
Made sentence more clear
Add PDO error handling details
Added namespace declaration to MainController.php.
Changed </components/yaml/introduction> to </components/yaml/format> per PR feedback.
[Validation] fixed a link
fix group sequence order
remove unmaintained translations
fix branch version used to base pull requests on
Added missing class to static callback example in PHP

Signed-off-by: Pedro Junior <v.ju.ni.or.v@gmail.com>