docs: add horizontal layout example

docs/src/.vuepress/config.ts

@@ -114,6 +114,7 @@ export default defineUserConfig<DefaultThemeOptions>({
             '/examples/hidden',
             '/examples/interaction',
             '/examples/multi',
+            '/examples/horizontal',
             '/examples/pinia',
             '/examples/stress',
           ],

docs/src/examples/horizontal.md

@@ -0,0 +1,19 @@
+---
+pageClass: examples
+
+---
+
+# Horizontal Layout
+
+Vue Flow doesn't require you to use vertical layouts.
+You can use horizontal layouts with the default node types as well.
+
+You can define where source or target handle positions are with the `sourcePosition` or `targetPosition` properties of nodes.
+
+<div class="mt-6">
+  <client-only>
+    <Suspense>
+      <Repl example="horizontal"></Repl>
+    </Suspense>
+  </client-only>
+</div>