feat: Dockerize demo projects

[scissorsneedfoodtoo]

Checklist:

• I have read freeCodeCamp's contribution guidelines.
• My pull request has a descriptive title (not a vague title like Update index.md)

Sorry all, this is a big one.

This PR Dockerizes all the projects in this repo, and uses Docker Compose to make building and starting multiple projects locally a bit easier.

I tried to keep a light touch with the individual projects. Most updates to projects are to fix issues with Rollup that I ran into, or to fix a bug after recent package version bumps from Renovate.

If it's easier, I can create new PRs for those project fixes. I think there were just one or two, one being the update to server.js for the Build a Pinterest Clone project.

Another big change was tweaking the method to refresh the access token for the Twitch Proxy project and moving those scripts into that project's directory. That project's container will also need to be set up to restart when it fails so that it can fetch a new access token every month, but that will probably depend on how the project is deployed.

Finally, the tests were simplified, and there's a new test to check the status code for every project.

Edit: These commits are all over the place, and I'd be happy to squash them if that makes things easier :)

[scissorsneedfoodtoo]

Thanks for your patience @raisedadead. I went through the projects and replaced any short links I could find outside of the examples in the URL Shortener Microservice project. I also replaced updated a few other links to serve files from our CDN.

This should be ready for another round of reviews.

[scissorsneedfoodtoo]

Note: The last commit bumps the Node version for all containers to v18, and requires Node v18 and npm v9 in the main package.json file.

[raisedadead]

OK - I have added some changes to the Docker Compose based setup. I would like to have it tested, though.

In theory, you should be able to do this as a first-time contributor:

1. Clone and Checkout this PR's branch.

2. Run these commands:

   cp sample.env .env
   npm ci
   npm run start

Do note that your machine will need Docker (or Docker Desktop). Some apps need legit env keys, but that is OK. You can ignore those apps.

Finally, to confirm everything is working, visit any app, for example, like so:

https://weather-proxy.localhost

[raisedadead]

Once you are done, do not forget to clean up with the following:

docker compose down
docker system prune --volumes --all --force

[ShaunSHamilton]

To confirm: I was able to get this up and running with the suggested instructions.

I only visited a few of the sites, but there were no errors from docker.