Add a PKGBUILD file

[Pavel Dvořák]

When building and installing Crusta I got two errors:

• crusta binary could not be created, because there already is crusta directory (rename worked)
• PKGBUILD file is missing

I created some really basic one, but better would be to create proper one

(OS: Arch Linux, package manager: pamac)

[mmetak]

https://aur.archlinux.org/packages/crusta-browser-git/

[Anmol Gautam]

thanks @mmetak