Add copilot theme, start sketching out the auth modal

styles/src/styleTree/copilot.ts

@@ -0,0 +1,11 @@
+import { ColorScheme } from "../themes/common/colorScheme"
+import { text } from "./components";
+
+
+export default function copilot(colorScheme: ColorScheme) {
+    let layer = colorScheme.highest;
+
+    return {
+        authModal: text(layer, "sans")
+    }
+}