Add mkdocs-jupyter plugin for notebook rendering

[negin513]

This PR adds Jupyter notebook support via mkdocs-jupyter to the documentation:

• Adds support for rendering Jupyter notebooks (.ipynb) as documentation pages using the mkdocs-jupyter plugin
• Adds mkdocs-jupyter to conda.yaml dependencies and configures the plugin in mkdocs.yml

To see how a notebook looks like, see the template repo example.