message: docs: fix headers in "Getting Started" code-snippets
  The headers of two of the code-snippets in the [Input section](https://angular.io/start#input)
  of the "Getting Started" guide incorrectly referenced an non-existent
  file path (`src/app/product-list/product-alerts.component.ts`).
  This commit fixes the headers to show the correct file path
  (`src/app/product-alerts/product-alerts.component.ts`).
  Fixes
  PR Close
diff: @@ -255,11 +255,11 @@ The next step is to create a new alert feature that takes a product as an input.
  1. Import `Input` from `@angular/core`.
  - <code-example path="getting-started/src/app/product-alerts/product-alerts.component.1.ts" region="imports" header="src/app/product-list/product-alerts.component.ts"></code-example>
  + <code-example path="getting-started/src/app/product-alerts/product-alerts.component.1.ts" region="imports" header="src/app/product-alerts/product-alerts.component.ts"></code-example>
  1. In the `ProductAlertsComponent` class definition, define a property named `product` with an `@Input()` decorator. The `@Input()` decorator indicates that the property value passes in from the component's parent, the product list component.
  - <code-example path="getting-started/src/app/product-alerts/product-alerts.component.1.ts" region="input-decorator" header="src/app/product-list/product-alerts.component.ts"></code-example>
  + <code-example path="getting-started/src/app/product-alerts/product-alerts.component.1.ts" region="input-decorator" header="src/app/product-alerts/product-alerts.component.ts"></code-example>
  1. Define the view for the new product alert component.
  