add new widgets; rewrite workspace indicator

lua/widgets/bar/clock.lua

@@ -0,0 +1,18 @@
+local datetime = Variable(0):poll(1000, "date +'%d %b %H:%M:%S'", function(out, _) return out end)
+local unix_seconds = Variable(0):poll(1000, "date +'%s'", function(out, _) return out end)
+
+return Widget.Box({
+  class_name = 'clock',
+  vertical = true,
+  valign = 'CENTER',
+  children = {
+    Widget.Label({
+      halign = 'START',
+      label = bind(datetime, 'value')
+    }),
+    Widget.Label({
+      halign = 'START',
+      label = bind(unix_seconds, 'value')
+    })
+  }
+})