tools: add dpi get-all to the ratbagctl man page
@@ -100,6 +100,9 @@ resolution of the active profile if none are given.
.B dpi get
Print the dpi value
.TP 8
+.B dpi get-all
+Print the supported dpi values
+.TP 8
.B dpi set N
Set the dpi value to N
.SH Rate Commands
