* Bump version to v0.2.0

* Add changelog

* minor refine

* minor refine

* update date

* clean the code

* minor refine

* update release date

* Fix grammar

* Fix grammar

* Fix grammar

* Fix grammar

* Minor refine

* Fix error format in readme

* update date

* minor refine

* minor refine

* minor refine

* minor refine

* refine grammar