Make sure docker-compose up works with default Docker setup

[arikfr]

I don't know if this is always the case, but docker-compose up -d just failed for me on a clean install of Windows because of the memory issue with webpack (the need to have at least 4GB of memory). I have a feeling it only works when:

1. running on Linux (and the host has enough memory)
2. running on Windows/Mac with memory allocated to Docker already increased

This is a terrible experience for contributors and I think we should invest some effort in fixing this. I see two options here, but happy to hear suggestions:

1. Make sure webpack can work with default settings (2GB of memory). Using webpack 4 on a large project (or, how to avoid "JavaScript heap out of memory" with production mode) webpack/webpack#6389 has some relevant discussion.
2. Make development setup skip building frontend assets as they're not needed anyway (being overwritten by local ones).

[arikfr]

npm run build also won't work on Windows because rm is not a recognized command.