feature: add Svelte framework to app, refactor tracking panel into Svelte component

lib/frontend/stores/configStore.js

@@ -0,0 +1,30 @@
+import { writable } from 'svelte/store'
+
+const createConfigStore = () => {
+  const state = JSON.parse(localStorage.getItem('fb-to-ical-config') || '{}')
+
+  const { subscribe, set, update } = writable(state)
+
+  const setValue = (key, value) => {
+    update((prevState) => {
+      const nextState = {
+        ...prevState,
+        [key]: value,
+      }
+
+      localStorage.setItem('fb-to-ical-config', JSON.stringify(nextState))
+
+      return nextState
+    })
+  }
+
+  return {
+    ...state,
+    subscribe,
+    set,
+    update,
+    setValue,
+  }
+}
+
+export default createConfigStore()