docs: add signal forms custom controls guide

Co-authored-by: Leon Senft <[email protected]>

docs: add signal forms custom controls guide

Author: bencodezen

adev/src/app/routing/sub-navigation-data.ts

@@ -452,6 +452,11 @@ const DOCS_SUB_NAVIGATION_DATA: NavigationItem[] = [
                 path: 'guide/forms/signals/validation',
                 contentPath: 'guide/forms/signals/validation',
               },
+              {
+                label: 'Custom controls',
+                path: 'guide/forms/signals/custom-controls',
+                contentPath: 'guide/forms/signals/custom-controls',
+              },
               {
                 label: 'Comparison with other form systems',
                 path: 'guide/forms/signals/comparison',

adev/src/content/examples/signal-forms/src/login-validation/app/app.html

@@ -7,7 +7,7 @@
 
     @if (loginForm.email().touched() && loginForm.email().invalid()) {
       <ul class="error-list">
-        @for (error of loginForm.email().errors(); track $index) {
+        @for (error of loginForm.email().errors(); track error) {
           <li>{{ error.message }}</li>
         }
       </ul>
@@ -22,7 +22,7 @@
 
     @if (loginForm.password().touched() && loginForm.password().invalid()) {
       <div class="error">
-        @for (error of loginForm.password().errors(); track $index) {
+        @for (error of loginForm.password().errors(); track error) {
           <p>{{ error.message }}</p>
         }
       </div>