Fix User Guide Search button issue

Signed-off-by: Hashem Qolami <hashem@qolami.com>
Merge pull request #2544 from HashemQolami/user-guide-patch

Fix User Guide CSS Issue
[ci skip] Add a missing semicolon in the docs css
[ci skip] Some spaces & docblock fixes
Merge branch 'develop' of /Users/neko/github/CodeIgniter/user_guide_src/ into develop_japanese