Adding .dockerignore file

[samikeijonen]

I haven't studied yet much about .dockerignore file. But what we do know is that Apple M1 Pros are super slow when starting Docker.

Issue could be for example lot's of files in node_modules folder. Maybe Adding .dockerignore file solves this issue.

[pekkakortelainen]

Yes, node_modules can get quite bulky. We'll investigate the possibilities .dockerignore can offer.

Thanks for opening this issue!