headlamp-build: Add package.json with scripts from Makefile

[illume]

This is to simplify using Headlamp so that people do not need to have gnu Make installed. Which isn't on Windows, and isn't on some Mac/unix systems.

Only has the start command t Note: This package is not intended to be published, and so the name is not important at this stage.

• [x] Add backend and frontend related targets
• [x] npm start works in root assuming you have node and golang installed
• [x] updated contrib guide to remove Makefile mentions
• [x] test WSL ubuntu
• [ ] test Mac
• [ ] test Windows cmd / powershell

[sniok]

nice! since this is just a beginning I'd like to suggest a convention for package script names which I've seen in other projects where ":" character separates groups and "-" separates rest, like this:

frontend:run
frontend:install-ci
frontend:coverage
backend:run
backend:coverage-html
etc..

another suggestion is to use npm run --prefix frontend ... instead of cd frontend && npm run ...

also I'm not sure if it's just me but I'd like to avoid duplicated commands like run backend and backend run. I know this might be a convenient shortcut for people that already used to one way or the other but I think having just one variant might be cleaner