* Remove note about contacting sir@cmpwn.com to package Sway for other
distros
* Add swaybg as an optional dependency
* Make it clear that gdk-pixbuf2 is only necessary for extra image
formats for system tray
* Mark git as an optional dependency
* Add trailing slash to the 'build/' folder, in accordance with the
English instructions
- Optional since Sway 1.6 per swaywm/wlroots@bad1e9afa8
- Deprecated in Sway 1.7 per 67d3d952b6
- Removed in Sway 1.8 per e5728052b5
- Ignored in future versions (keeps root priveleges)