Fix typo in doc/ja/array/constructor
Fix typo in doc/ja/core/semicolon
Fix typo in doc/ja/core/delete
Standardize a word for "strict" in ja
Improve a line in doc/ja/core/delete

I guess ":" is a typo. But changing line is better than fix it.
Improve expression in doc/ja/object/prototype
Improve expression in doc/ja/other/timeouts

Clarify "don't have to" or "must not" in japanese.
I guess origin looks like "must not" than "don't have to".