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/notification.d.ts

@@ -1,3 +1,5 @@
+import icons from "modules/icons/index";
+
 export interface NotificationArgs {
     appName?: string;
     body?: string;
@@ -9,3 +11,5 @@ export interface NotificationArgs {
     timeout?: number;
     transient?: boolean;
 }
+
+export type NotificationIcon = keyof typeof icons.notifications;