docs(examples): helper lines (#1915)

feat: add optional chaining to prevent types errors and add an example of helper lines (#1904)

* docs: code errors in "Updating Node Data" (#1900)

fix(docs): Example of fixing code errors in "Updating Node Data"

* fix: add optional chaining to prevent errors in link filtering

* feat: add an example of helper lines

* refactor: In the HelperLines example, replace the observer with dimensions

---------

Co-authored-by: Charles Lee <114982593+rookie-orange@users.noreply.github.com>
Co-authored-by: J <gongjie0422@163.com>

docs/src/.vitepress/config.mts

@@ -31,7 +31,7 @@ function typedocSidebarEntries() {
 
     if (module === 'variables') {
       children = children.filter((child) => {
-        return child.link.includes('default')
+        return child.link?.includes('default')
       })
     }
 
@@ -218,6 +218,7 @@ export default defineConfigWithTheme<DefaultTheme.Config>({
             { text: 'Viewport Transition', link: '/examples/transition' },
             { text: 'Teleport Nodes', link: '/examples/teleport' },
             { text: 'Stress Test', link: '/examples/stress' },
+            { text: 'Helper Lines', link: '/examples/helper-lines' },
           ],
         },
         {

docs/src/examples/helper-lines.md

@@ -0,0 +1,7 @@
+# Helper Lines
+
+Visual guides and snapping for nodes while dragging.
+
+<div class="mt-6">
+  <Repl example="helperLines"></Repl>
+</div>