docs(migrations): Fix indentation in documentation for signal inputs migration (#60204)

PR Close #60204

adev/src/content/reference/migrations/signal-inputs.md

@@ -49,18 +49,18 @@ export class MyComponent {
 import {Component, input} from '@angular/core';
 
 @Component({
-template: `Name: {{name() ?? ''}}`
+  template: `Name: {{name() ?? ''}}`
 })
 export class MyComponent {
-readonly name = input<string>();
+  readonly name = input<string>();
 
-someMethod(): number {
-const name = this.name();
-if (name) {
-return name.length;
-}
-return -1;
-}
+  someMethod(): number {
+    const name = this.name();
+    if (name) {
+      return name.length;
+    }
+    return -1;
+  }
 }
 </docs-code>