audio: added and linked playerctl and sxhkd

wiki/linux/sxhkd.md

@@ -0,0 +1,43 @@
+# SXHKD
+
+[SXHKD](https://github.com/baskerville/sxhkd) - short for Simple
+[X](/wiki/linux/x_window_system.md) hotkey daemon - is a program to set hotkeys.
+
+## Setup
+
+On most linux distributions SXHKD can be installed with the `sxhkd`
+package.
+Alternatively it can be installed via
+[Github](https://github.com/baskerville/sxhkd).
+
+## Usage
+
+### Setting a Hotkey
+
+Configuration for setting hotkeys is done in the file `~/.config/sxhkd/sxhkdrc`.
+A hotkey corresponds to typically two, sometimes more lines within this
+configuration file.
+The first line describes the keys that act as hotkeys and the second line
+describes the commands that are run on pressing the hotkey.
+
+There are simple hotkeys using only one key (in this case the Launch Button).
+
+```txt
+XF86LaunchB
+	xdotool selectwindow | xsel -bi
+```
+
+And some commands use modifier keys or multiple keys.
+
+```txt
+super + shift + equal
+	sxiv -rt "$HOME/image"
+```
+
+When using similar commands it can be useful to map multiple hotkeys in one
+entry.
+
+```txt
+super + {_,shift + }{h,j,k,l}
+	bspc node -{f,s} {west,south,north,east}
+```