Fixed document for multisort in BaseArrayHelper 

Fixed
Merge pull request #3356 from netyum/patch-2

Fixed document for multisort in BaseArrayHelper
Fixed wrong links [skip ci]
Update concept-behaviors.md

fixed spelling
Merge pull request #3359 from tsvetann/patch-4

Update concept-behaviors.md
updated guide toc [skip ci]
Cleaned Up

No major changes. Looks good!
Edited up through "I18N"
Catalan translation
Merge pull request #3363 from larnu/master

Catalan translation
renamed chapter to section [skip ci]
Edited up to Active Record
Finished Edits
typo

[ci skip]
Rough creation of a doc style guide

Should have started this before; important to maintain consistency.