default channel not on Jupyter server for conda chapter #113

When you do:

conda config --show channels

in the Jupyter server, you get:

channels:
  - conda-forge

instead of

channels:
  - defaults

Which messes up the flow of the lesson a bit.

I don't think this is important enough to fix before we teach, but we should adapt the notes so they are correct when using the Jupyter server, with a note saying things would likely look different on your local computer.