follow geoscixyz-labs

[lheagy]

• sync notebooks to geoscixyz-labs using nblibrarian
• follows the same instructions as: https://github.com/geoscixyz/geosci-course

@sgkang: this will make sure that all of the notebooks that you point to are up to date for the course.

cc @yangdikun: this is an example of how to use nblibrarian to assemble a repo that follows geosci-labs.