[BUG] Document skip_imports

[bkreider]

Description of expected behavior and the observed behavior

I don't think skip_imports is documented. I found without this setting, a command like: anaconda-project list-commands will recursively search every subdirectory for notebooks and then complain that no command runs that notebook. This was taking 50s for me on a windows machine with multiple environments.

skip_imports:
    notebooks: true

[jbednar]

Documenting it is good, but also I think it should be false by default. Rarely useful, often problematic.

[AlbertDeFusco]

I agree on changing the default. I'll get some time soon to work towards a release.