Include working example of running a server
### Feature description

It would be great if the documentation had a working example of running a server

Here is an example:

#### Create a simple node project and install packages

```bash
  mkdir postgraphile_v5_node_example
  cd postgraphile_v5_node_example
  npm init -y
  npm install -D @tsconfig/node20 @types/express @types/node typescript
  npm install express postgraphile@beta
```

#### Add start script to package.json

```json
  "scripts": {
    "start": "GRAPHILE_ENV=development node --experimental-strip-types --watch index.ts"
  },
```

#### Create or modify tsconfig.json to

```json
{
  "compilerOptions": {
    "target": "ES2022",
    "module": "NodeNext",
    "moduleResolution": "nodenext"
  }
}
```


#### Create a simple server in typescript

Create index.ts with these contents

```TypeScript
import express from "express";
import { createServer } from "node:http";
import { postgraphile } from "postgraphile";
import { makePgService } from "postgraphile/adaptors/pg";
import { grafserv } from "postgraphile/grafserv/express/v4";
import { PostGraphileAmberPreset } from "postgraphile/presets/amber";

/** @type {GraphileConfig.Preset} */
const preset = {
  extends: [PostGraphileAmberPreset],
  pgServices: [
    makePgService({
      connectionString: "postgres://yourusername:yourpossword@localhost:5432/yourdatabase",
      schemas: ["public"], // change schema here if needed
    }),
  ],
  grafast: {
    explain: true,
  },
};
(async () => {
  const app = express();
  const server = createServer(app);
  server.on("error", (e) => {
    console.dir(e);
  });
  const pgl = postgraphile(preset);
  const serv = pgl.createServ(grafserv);
  await serv.addTo(app, server);
  server.listen(5050, () => {
    console.log("Server listening at http://localhost:5050");
  })
})();
```

#### Run from command line and open GraphiQL UI

```bash
npm run start
```

Open browser and navigate to http://localhost:5050 to view the GraphiQL UI



### Motivating example

Could not find any working examples in documentation

### Breaking changes

None

### Supporting development

- [x] am interested in building this feature myself
- [x] am interested in collaborating on building this feature
- [x] am willing to help testing this feature before it's released
- [x] am willing to write a test-driven test suite for this feature (before it exists)
- [ ] am a [Graphile sponsor](https://www.graphile.org/sponsor/) ❤️
- [ ] have an active [support or consultancy contract](https://www.graphile.org/support/) with Graphile
