Do not use special characters in the file name
Do not use special characters in the file name
Do not use special characters in the file name
Improved API folder structure
Added callbacks intro
Fix a code formatting issue

Signed-off-by: xchs <github@gmx.net>
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.