add sketchybar mac settings and plugins, add skhd new key binds

configs/sketchybar_m/plugins/volume.sh

@@ -0,0 +1,20 @@
+#!/bin/sh
+
+# The volume_change event supplies a $INFO variable in which the current volume
+# percentage is passed to the script.
+
+if [ "$SENDER" = "volume_change" ]; then
+  VOLUME=$INFO
+
+  case $VOLUME in
+    [6-9][0-9]|100) ICON="􀊩"
+    ;;
+    [3-5][0-9]) ICON="􀊥"
+    ;;
+    [1-9]|[1-2][0-9]) ICON="􀊡"
+    ;;
+    *) ICON="􀊣"
+  esac
+
+  sketchybar --set $NAME icon="$ICON" label="$VOLUME%"
+fi