Allow package-relative src

[bollwyvl]

Elevator Pitch

Expand the src spec to allow for starters relative to a python package.

Motivation

Distributing a simple starter with a package needs to be really easy. Including jupyter_notebook_config.d JSON is not super easy. It should be possible to specify a package as the root of a config location.

Design Ideas

• introduce a new key, e.g. py_src which gets imported, has the __file__ interpreted, and prepended to the source
  • e.g. py_src: module_name
• offer a jinja function which can be used in the src,
  • e.g. src: '{{ py_src("module_name') }}/path/to/file.json'
• introduce a custom syntax in src
  • e.g. src: 'module_name:path/to/file.json'

[bollwyvl]

closed by #25