Rich-argparse

Features
- [GH-4](https://github.com/hamdanal/rich-argparse/issues/4),
[PR-9](https://github.com/hamdanal/rich-argparse/pull/9)
Metavars now have their own style `argparse.metavar` which defaults to `'bold cyan'`

Fixes
- [GH-4](https://github.com/hamdanal/rich-argparse/issues/4),
[PR-10](https://github.com/hamdanal/rich-argparse/pull/10)
Add missing ":" after the group name similar to the default HelpFormatter
- [PR-11](https://github.com/hamdanal/rich-argparse/pull/11)
Fix padding of long options or metavars
- [PR-11](https://github.com/hamdanal/rich-argparse/pull/11)
Fix overflow of text in help that was truncated
- [PR-11](https://github.com/hamdanal/rich-argparse/pull/11)
Escape parameters that get substituted with % such as %(prog)s and %(default)s
- [PR-11](https://github.com/hamdanal/rich-argparse/pull/11)
Fix flaky wrapping of long lines

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