Update readthedocs landing page to display software "title"

[stscijgbot]

Issue JP-1215 was created by Alicia Canipe:

There was a request from the JDox Working Group to add a more descriptive title to the jwst software readthedocs landing page ([https://jwst-pipeline.readthedocs.io/en/latest/).|https://jwst-pipeline.readthedocs.io/en/latest/)] Since we are now trying to point mainly to the software readthedocs in the Data Calibration and Analysis JDox pages, the working group suggests adding a title to the software documentation landing page to let users know for sure that they are in the right space (for comparison, [http://docs.astropy.org/en/stable/] )