Mistakes in documentation
<!-- Before opening an issue: if you use `npm` try running `yarn` instead; if
      you run `yarn`, please try running `npx yarn-deduplicate && yarn`. -->

<!-- You can also chat with us on Discord: http://discord.gg/graphile -->

### Summary

I'm trying to run beta version of Postgraphile and have encountered with some mistakes in documentation. First, the example of starting server on https://postgraphile.org/postgraphile/next/usage-library not completely correct and this is how I it works in typescript:
```typescript
import { createServer } from "node:http";
import postgraphile from "postgraphile";
import { grafserv } from "grafserv/dist/servers/express/v4"; // <- Notice this
import express from 'express';

import preset from "./graphile.config";

export const pgl = postgraphile(preset);
const serv = pgl.createServ(grafserv);


const app = express();
const server = createServer(app);
server.on("error", () => {});
serv.addTo(app, server).catch((e) => {
  console.error(e);
  process.exit(1);
});
server.listen(5678);

console.log("Server listening at http://localhost:5678");
```
this is caused by the fact that grafserv has no direct exports, so that it must be imported from `dist` directory.
The second problem is with configuration. I tried to set configuration according to https://postgraphile.org/postgraphile/next/config, but here I encountered the same problem and this is how my config looks like:
```typescript
import "graphile-config";
import "postgraphile";

import { PostGraphileAmberPreset } from "postgraphile/dist/presets/amber"; // <- again, a dist

const preset: GraphileConfig.Preset = {
  extends: [PostGraphileAmberPreset],
};

export default preset;
```
then I tried to connect to Postgres database, which should be done using 'makePgService' function, but I have looked through all the `postgraphile` package and haven't found where I can import this function from.

### Additional context

<!-- Please provide additional context such as environment versions (including
      operating system, Node, PostgreSQL, Redis, etc. as relevant), software
      versions (from `yarn.lock`) or similar, plugins in use, database schema
      if relevant, bundler (if any). -->
