Add dashboard to build

reminder-dashboard/src/components/App/TimezoneProvider.tsx

@@ -0,0 +1,20 @@
+import { createContext } from "preact";
+import { useContext } from "preact/compat";
+import { useState } from "preact/hooks";
+import { DateTime } from "luxon";
+
+type TTimezoneContext = [string, (tz: string) => void];
+
+const TimezoneContext = createContext(["UTC", () => {}] as TTimezoneContext);
+
+export const TimezoneProvider = ({ children }) => {
+    const [timezone, setTimezone] = useState(DateTime.now().zoneName);
+
+    return (
+        <TimezoneContext.Provider value={[timezone, setTimezone]}>
+            {children}
+        </TimezoneContext.Provider>
+    );
+};
+
+export const useTimezone = () => useContext(TimezoneContext);