Support Custom GitHub Actions

[TsuyoshiUshio]

Support Custom GitHub Actions for doing:

• Run BlogBabel Command Line tool in GitHub Actions.
• Read md/config file as Source that is reside in a repo.
• Translate it to the target blogs with configuration

Customers don't need to set up their machine or download the binary.

[TsuyoshiUshio]

Working on it. Created a repo. https://github.com/TsuyoshiUshio/blogbabel-action