add original docs
translate Selectors
translate variables
Merge pull request #4 from mitsuruog/translate

[監訳希望] Selectors
remove original sentence
Merge pull request #5 from mitsuruog/translate

[監訳済み] Selectors
Merge https://github.com/enja-oss/stylus
Fix some
Fi
Merge pull request #6 from mitsuruog/master

[監訳希望] Variables