Add basic PKGBUILD for Arch Linux and derivatives

[lainedfles]

This is a simple functional PKGBUILD file. Can be used like:

1. Set desired release tag version within PKGBUILD
2. Change directory into the same path as the PKGBUILD
3. Execute updpkgsums to download the tag and calculate the checksum(s)
4. Build and install with makepkg -si

Thanks!