.npmrc mounting

[atoff]

Is your feature request related to a problem? Please describe.
Some of the projects that I work on use GitHub packages to serve their package to NPM. This requires you to use a Personal Access Token to authenticate with the repo, which can be done via command line. However, when you restart the container, this is forgotten. You can use an .npmrc file to save these credentials ref.

Describe the solution you'd like
Ability to mount an .npmrc into the ~/.npmrc path

Describe alternatives you've considered
Could do per-project and gitignore, but if you are using multiple projects in one instance this isn't ideal

Additional context