updated vector data and visualisation notebook

[krishnaglodha]

I have enhanced the current notebook by adding vector data code from my notebooks.

For visualisation, I have added abilities to show popup

[justb4]

Thanks for this contribution! So overall this PR adds (nothing is deleted):

• GeoPandas sections to chapter 4 "Vector Data" [4]
• ipyleaflet popups to Chapter 7 "Visualization" [7]

Both additions are valuable, no comments on [7]. Any issues with execution (did not have time) can be fixed on the fly.
Some comments on [4]:

• GeoPandas should definitely be in. There is quite some text/cells now. Suggestion: split into a "Quickstart" and optional "More GeoPandas". Mainly for time (4h workshop) reasons.
• add some text on comparing OGR, Fiona and GP.
• knowledge of Pandas is assumed (is just like a pandas DataFrame), introduce Pandas.
• Postgis example: does the Notebook assume running Postgres/PostGIS locally?
• aren't extra dependencies, like GeoPandas, needed in the Dockerfile ?

Maybe @tomkralidis @francbartoli @pvgenuchten @kalxas @ et al can take a look at this PR as well? After some of the above comments fixed, I think we can merge, run, review and fix from there. It is hard to review notebooks from within GitHub.

[tomkralidis]

• GeoPandas is already a requirement
• turn PostgreSQL/PostGIS executable cells into text with suggestion text if folks have PostgreSQL/PostGIS and load data, to run sample Python code