Add a function that reads named_features.csv into a pandas DataFrame

[cjtu]

The pandas package excels at storing and manipulating tabular data. The file /data/named_features.csv is a table of named features on Pluto and some facts about them.

Write a function in helpers.py that:

• reads the named_features.csv into a pandas dataframe

Add an example in jupyter_notebooks/ (you can edit tutorial.ipynb or make your own notebook) which shows how to call this function and some cool manipulations you can do with pandas methods.

[katpowell]

I can work on this