Improve docs (#2)

* fix README

* upgrade `ex_doc`

* add live examples

* use check mark instaed of `v`

* bump up 0.1.2

* fix GitHub Actions Workflow

* add dialyzing on workflow

fix link

Squashed commit of the following:

commit 39e40a0b547dd32db3eaaadcbc832a698d0aaf74
Author: Eiji MATSUMOTO <[email protected]>
Date:   Fri Apr 30 11:41:37 2021 +0900

    rename modules and functions

commit 8d55dbf2e5085a385c45c62daed1736f01054537
Author: Eiji MATSUMOTO <[email protected]>
Date:   Fri Apr 30 11:40:25 2021 +0900

    rename test modules and functions