Add key definitions

arch-config/.config/sway/config

@@ -4,6 +4,17 @@
 #
 # Read `man 5 sway` for a complete reference.
 
+# $Mod = WINDOWS key or Super key or Mod4
+# Mod1 = ALT key
+# Control = CTRL key
+# Shift = SHIFT key
+# Escape = ESCAPE key
+# Return = ENTER or RETURN key
+# KP_Enter = Keypad Enter
+# Pause = PAUSE key
+# Print = PRINT key
+# Tab = TAB key
+
 ### Variables
 
 # Logo key. Use Mod1 for Alt.