Fixed warning "Title underline too short"
[ja] Follow #774
[ja] Follow #820
[ja] Follow #823
[ja] Fixed typo
Correct grammar in advanced installation docs
Merge pull request #863 from bcrowe/hotfix-advInstGrammar

Correct grammar in advanced installation docs
Merge pull request #858 from bcrowe/hotfix-tree

Change indented to underscored in Tree behavior docs
Correct grammar in installation docs
Fix proper name for GitHub
Merge pull request #864 from bcrowe/hotfix-inst

Correct grammar in installation docs
Update minor grammar issue in data-validation.rst
Merge pull request #865 from Harreh/patch-1

Update minor grammar issue in data-validation.rst
Double rainbow word
Merge pull request #866 from bar/patch-1

Double rainbow word
[ja] Follow #778
[ja] Follow #825
Fixed bug in ArticleController.php example.
Merge pull request #867 from Harreh/patch-1

Fixed bug in ArticleController.php example.
[ja] Follow #847