Init rebase to Svelte and TS

src/lib/stores/theme.ts

@@ -0,0 +1,17 @@
+import { writable } from 'svelte/store';
+
+function getInitalTheme(): string {
+	if (typeof window === 'undefined') return 'dark';
+
+	const savedTheme: string | null = localStorage.getItem('theme');
+	if (savedTheme === 'dark' || savedTheme === 'light') return savedTheme;
+
+	const sysPrefTheme = window.matchMedia('(prefers-color-scheme: dark)').matches;
+	return sysPrefTheme ? 'dark' : 'light';
+}
+
+export const theme = writable(getInitalTheme());
+
+theme.subscribe((value) => {
+	if (typeof window !== 'undefined') localStorage.setItem('theme', value);
+});