Minor documentation fixes.
added missing option 'label_catalogue' for dashboard groups in di configuration
added feature to wire extensions dynamically using configuration
enhance and update bulgarian translation
remove slugify filter in tab id generation

slugify function doesn't work correctly on Russian symbols, so we may use index of tab without name
Merge pull request #1354 from wiistriker/patch-1

remove slugify filter in tab id generation
Merge pull request #1353 from bmanolov/bg-translation

Enhance and update bulgarian translation
Merge pull request #1352 from sjopet/extensions

added feature to wire extensions dynamically using configuration
Merge pull request #1349 from virtualize/master

added missing option 'label_catalogue' for dashboard groups in di config
Merge pull request #1297 from pezia/master

Minor documentation fixes
Merge branch 'sonata/master'