Implementing a GraphQL API in a backend

We are now going to set up GraphQL in our existing blog application backend in addition to the REST API. Doing so will allow us to see how GraphQL compares to and differs from a REST API. Follow these steps to get started setting up GraphQL on the backend:

1. Copy the existing ch10 folder to a new ch11 folder, as follows:

   $ cp -R ch10 ch11

2. Open the ch11 folder in VS Code.
3. First, let’s install a VS Code extension to add GraphQL language support. Go to the Extensions tab and search for the GraphQL.vscode-graphql extension developed by the GraphQL Foundation. Install the extension.
4. Next, install the graphql and @apollo/server libraries in the backend using the following commands:

   $ cd backend/
   $ npm install graphql@16.8.1 @apollo/server@4.10.0

   Apollo Server is a production-ready GraphQL server implementation that supports multiple backend web frameworks, including Express.

5. Create a new backend/src/graphql/ folder. Inside it...