niri: add waybar

niri/.config/waybar/dark.css

@@ -0,0 +1,12 @@
+* {
+    background-color: #282e38;
+    color: #a29e98;
+}
+
+#workspaces button.active {
+    border-bottom: 3px solid #04785d;
+}
+
+#workspaces button.urgent {
+    border-bottom: 3px solid #c37583;
+}