Comment out line and yank it?

This plugin (for evil mode in emacs), is inspired by vim-commentary:
[evil-commentary](https://github.com/linktohack/evil-commentary)

Maybe it would be good to have a circle of inspiration and implement the extra features `evil-commentary` adds:
```
;;   gy = comment operator but also yank to register x (i.e. "xgy...)
;;   gyy = comment current line and yank
```