add old content and a warning to the events page

docs/src/docPages/api/events.md

@@ -1 +1,34 @@
-# Events
+# Events
+
+:::warning Out of date
+This content is written for tiptap 1 and needs an update.
+:::
+
+There are some events you can listen for. A full list of events can be found [here](/api/classes.md#editor-options).
+
+```js
+const editor = new Editor({
+  onInit: () => {
+    // editor is initialized
+  },
+  onUpdate: ({ getHTML }) => {
+    // get new content on update
+    const newContent = getHTML()
+  },
+})
+```
+
+It's also possible to register event listeners afterwards.
+
+```js
+const editor = new Editor(…)
+
+editor.on('init', () => {
+  // editor is initialized
+})
+
+editor.on('update', ({ getHTML }) => {
+  // get new content on update
+  const newContent = getHTML()
+})
+```