Added the store for dynamically changing the popup titles

src/routes/+layout.svelte

@@ -4,6 +4,7 @@
   import Footer from "$components/layout/Footer.svelte";
   import { initializeLinksReplacement } from "$lib/popup-links";
   import { onDestroy } from "svelte";
+  import { headTitle } from "$stores/popup";
 
   interface Props {
     children?: import('svelte').Snippet;
@@ -22,6 +23,10 @@
   })
 </script>
 
+<svelte:head>
+  <title>{$headTitle}</title>
+</svelte:head>
+
 <Header/>
 <main>
   {@render children?.()}

src/stores/popup.ts

@@ -0,0 +1,15 @@
+import { derived, writable } from "svelte/store";
+import { PLUGIN_NAME } from "$lib/constants";
+
+/**
+ * Store containing the name of the subpage. This name will be added to the title alongside the name of the plugin.
+ */
+export const popupTitle = writable<string | null>(null);
+
+/**
+ * Name of the current route with the name of the plugin appended to it.
+ */
+export const headTitle = derived(
+  popupTitle,
+  $popupTitle => ($popupTitle ? `${$popupTitle} | ` : '') + PLUGIN_NAME
+);