Render jupyter notebooks in html in gitea

[robe]

Per request of darkblueb.

Steps more or less detailed here - ​https://blog.gitea.io/2022/04/how-to-render-jupyter-notebooks-on-gitea/

But had to install ipython as well so:

sudo apt install python3-pip
pip3 install nbconvert
pip3 install ipython

and then added in the respective lines.

But I think I need to do somethng to enable css and strip the html cause it looks funny.

You can see an example here:

​https://dev.git.osgeo.org/gitea/osgeolive/OSGeoLive-Notebooks/src/branch/master/Shapely/shapely-point-in-poly.ipynb

There is also other things like rendering mathjax as detailed in this thread