Move error tracking and analytics to their own files

src/app/analytics.ts

@@ -0,0 +1,17 @@
+import {page} from "$app/stores"
+
+const w = window as any
+
+w.plausible =
+  w.plausible ||
+  function () {
+    ;(w.plausible.q = w.plausible.q || []).push(arguments)
+  }
+
+export const setupAnalytics = () => {
+  page.subscribe($page => {
+    if ($page.route) {
+      w.plausible("pageview", {u: $page.route.id})
+    }
+  })
+}