report powerline-rs support
## `powerline-rs` template
I implemented support for the [`powerline-rs`](https://gitlab.com/jD91mZM2/powerline-rs) program, basically a re-implementation of `powerline` written in rust. I thought this soft is not vital, so I'd keep it as a third-party plugin. On the other hand, you have `vim-lightline` in the main project, and `powerline-rs` is basically the same thing for `zsh`/`bash`.

It's available in npm with
``` sh
npm install themer-powerline-rs
```
the source code is GPLv2, available [here](https://gitlab.com/lafleurdeboum/themer-powerline-rs) in gitlab. Would you consider adding the link to the community-contributed templates ? That would be fine enough for me.

Thank you for this great soft !
