Rich-argparse

Fixes
- [GH-5](https://github.com/hamdanal/rich-argparse/issues/5),
[PR-6](https://github.com/hamdanal/rich-argparse/pull/6)
Fix `RichHelpFormatter` does not replace `%(prog)s` in text
- [GH-7](https://github.com/hamdanal/rich-argparse/issues/7),
[PR-8](https://github.com/hamdanal/rich-argparse/pull/8)
Fix extra newline at the end

Initial release

Features
- First upload to PyPI, `pip install rich-argparse` now supported