Renamed hooks cookbook article
Restructured API folder

API = Application Programming Interface
in my opinion, hooks and callbacks are part of the developer API
Merge branch '2.11' into 3.0
Merge branch '3.0' into 3.1
Merge branch '3.1' into 3.2
Merge remote-tracking branch 'upstream/3.2' into 3.2.
Merge branch '3.2' into 3.2-ja.
Do not use special characters in the file name
Merge remote-tracking branch 'upstream/3.2' into 3.2.
Merge branch '3.2' into 3.2-ja.