Add Arch Linux install to README.md

[zquestz]

I used to be an avid Hotline user, came across Obsession, and love what you are working on.

I don't use a Mac anymore, so I figured I would get this running on my Arch Linux machine, and it was relatively simple! The patch was to get things building on Qt5, and I removed the empty debug file that gets created every time you run Obsession.

https://aur.archlinux.org/cgit/aur.git/tree/qt5.patch?h=obsession-git

Once I got it all working, I went ahead and packaged it up in the AUR for you.

https://aur.archlinux.org/packages/obsession-git

Here is a screenshot of it running on my Linux box!

Thanks for building an awesome Hotline client!

[tjohnman]

Thank you for your kind words! If we want to go with Qt 5 for an AUR build, we will have to maintain a branch specifically for it, I'm afraid, since we're using Qt 4 for the MacPorts build that targets old versions of MacOS.

Or maybe just maintaining the patch separately would be enough?

[zquestz]

I can maintain a patch. Just have a few more lingering questions in my other PR.

I am happy to handle it either way. Branch or patch.