Works with yarn.

src/default.d.ts

@@ -1,3 +1,4 @@
 declare module '@storybook/addon-svelte-csf';
 declare module 'prosemirror-svelte/state';
+declare module 'prosemirror-svelte/helpers/plugins';
 declare module 'daisyui';

src/lib/editor/examples/MarkdownEditor.ts

@@ -0,0 +1,26 @@
+import { EditorState, TextSelection } from 'prosemirror-state';
+import { schema, defaultMarkdownParser, defaultMarkdownSerializer } from 'prosemirror-markdown';
+import { corePlugins } from 'prosemirror-svelte/helpers/plugins';
+
+/**
+ * Create an empty editor state, for a multi-line editor schema
+ * @param content {string}
+ * @param plugins {array<Plugin>}
+ * @return {EditorState}
+ */
+export const createMarkdownEditor = (content = '', plugins = []) => {
+  let doc, selection;
+
+  if (content) {
+    const paragraphs = content.split('\n');
+    doc = defaultMarkdownParser.parse(content);
+    //selection = TextSelection.atEnd(doc);
+  }
+
+  return EditorState.create({
+    schema: schema,
+    doc: doc as any,
+    selection,
+    plugins: [...corePlugins, ...plugins]
+  });
+};

src/lib/editor/examples/RichTextEditor104.svelte

@@ -1,21 +1,16 @@
 <script lang="ts">
   import { onMount } from 'svelte';
-  import { Plugin, PluginKey } from 'prosemirror-state';
   import ProsemirrorEditor from 'prosemirror-svelte';
-  import { createRichTextEditor, clear, toHTML, toPlainText } from 'prosemirror-svelte/state';
-  import { schema, defaultMarkdownParser, defaultMarkdownSerializer } from 'prosemirror-markdown';
-  import { exampleSetup } from 'prosemirror-example-setup';
-  const html = `
-<h3>I am Rich</h3>
-<p>Hello there! I am Rich, a rich-text editor. </p>
-<p>Go ahead and edit me.</p>
-<p>You can change the format using the keyboard. E.g.: </p>
-<p><strong>Ctrl/Cmd-b</strong> will toggle text as <strong>bold</strong>.</p>
-<p><strong>Ctrl/Cmd-i</strong> will toggle text as <em>italic</em>.</p>
-<p><b>Ctrl-Shift-0</b> will set the block type to paragraph.</p>
-<p><b>Ctrl-Shift-1,2,3...</b> will set the block type to heading 1,2,3...</p>`;
+  import { clear, toHTML, toPlainText } from 'prosemirror-svelte/state';
+  import { createMarkdownEditor } from './MarkdownEditor';
+  const markdown = `
+# This is a H1
+
+* One
+* Two
+* Three`;
   let focusEditor: any;
-  let editorState = createRichTextEditor(html, exampleSetup(schema as any));
+  let editorState = createMarkdownEditor(markdown);
   function handleChange(event: any) {
     editorState = event.detail.editorState;
   }
@@ -24,7 +19,7 @@
     focusEditor();
   }
   function resetEditor(event: any) {
-    editorState = createRichTextEditor(html);
+    editorState = createMarkdownEditor(markdown);
     focusEditor();
   }
   function showHtml(event: any) {