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.

globals/variables.ts

@@ -0,0 +1,13 @@
+import { Opt } from "lib/option";
+import { HexColor, RecursiveOptionsObject } from "lib/types/options";
+
+export const isOpt = <T>(value: unknown): value is Opt<T> =>
+    typeof value === 'object' && value !== null && 'value' in value && value instanceof Opt;
+
+export const isRecursiveOptionsObject = (value: unknown): value is RecursiveOptionsObject => {
+    return typeof value === 'object' && value !== null && !Array.isArray(value);
+}
+
+export const isHexColor = (value: string): value is HexColor => {
+    return /^#([A-Fa-f0-9]{6}|[A-Fa-f0-9]{3})$/.test(value);
+}