Prebuilt artifacts

Following our build instructions step-by-step can be a very time-consuming task. To speed up the process, prebuilt artifacts are available.

Instead of running docker-compose build, you can pull container ipasim/build:
```
docker pull ipasim/build
```

Instead of running ./scripts/build.ps1, you can pull container ipasim/artifacts and then start the container like this:

docker pull ipasim/artifacts
docker tag ipasim/artifacts ipasim/build
docker-compose run --name ipasim ipasim powershell