docker: Tidy up V5 example and add to docs

[jemgillam]

We'd like help with the V5 Docker documentation, here are the pages which need updating:

https://postgraphile.org/postgraphile/5/running-postgraphile-in-docker
https://postgraphile.org/postgraphile/5/running-postgraphile-as-a-library-in-docker

Here is a linked issue comment with some more information:

We do not have docker hub images for V5 yet, but you can make one yourself; e.g.:

FROM node:20-slim
WORKDIR /app

RUN npm init -y && npm install postgraphile@beta @graphile-contrib/pg-many-to-many@beta @graphile/pg-aggregates@beta @graphile/simplify-inflection@beta graphile@beta postgraphile@beta postgraphile-plugin-connection-filter@beta @grafserv/persisted@beta @graphile-contrib/pg-omit-archived@beta

EXPOSE 5678
CMD ["npx", "--no-install", "postgraphile", "-n", "0.0.0.0"]

You'll then want to mount your graphile.config.mjs file so that Docker can read from it.

Here's an working example:

• https://github.com/benjie/ouch-my-finger/blob/main/docker-compose.yml
• https://github.com/benjie/ouch-my-finger/blob/main/Dockerfile

Originally posted by @benjie in #2466