Created intro text of the Twig Reference
Added functions section
Added filter section
Created tags section
Added 'almost core' bundles
Added missing dot in property path assembly.
Adding link to how to render templates
Adding link to @ParamConverter
Changed uses of we in security cookbooks
Removed space around dot operator.
[Book/installation] Fixed "image file not readable" warning
add JsonResponse exemple
Remove UniversalClassLoader from debugging recipe (composer autoload covers it)
Update cookbook/form/dynamic_form_generation.rst

fixed event type
Fix typo
Update components/http_foundation/sessions.rst

added missing backslash
Update components/http_foundation/sessions.rst

fixed typo
add router.request_context.base_url to cookbook entry
Fixed function name

Function name is not MetadataBag::getLastUpdate() but getLastUsed()
Minor grammar tweak in service container documentation