Added strict type checking to the project. (#236)

* Implement strict typing (WIP).

* changes

* Finish type checks

* Fix notification icon, matugen settings and update tsconfig.

* OSD Styling updates and added the ability to configure OSD duration.

lib/types/dropdownmenu.d.ts

@@ -0,0 +1,10 @@
+import { WindowProps } from "types/widgets/window";
+
+export type DropdownMenuProps = {
+    name: string;
+    child: any;
+    layout?: string;
+    transition?: any;
+    exclusivity?: Exclusivity;
+    fixed?: boolean;
+} & WindowProps;