Add paru

[Qelxiros]

This PR adds support for another pacman wrapper, paru. The wrinkle here is that I often find myself using paru <package> to search and install interactively, which doesn't work with emplace. However, this PR covers the paru -S <package> use case, which I think is worthwhile on its own. An implementation for the former would require significant new functionality, which would probably be better suited for a new project entirely.

• add paru
• include paru in README.md

[tversteeg]

Wow thanks a lot for the PR!

[tversteeg]

@all-contributors please add @Qelxiros for platform

[allcontributors[bot]]

@tversteeg

I've put up a pull request to add @Qelxiros! :tada: