Explain the example notebook options better

[dgarijo]

Right now you can describe or search. But here are a few things that need to be clarified:

• The URIs are not clickable, and that is fine. They are ids that right now don't resolve, but it should be clarified or users will be confused.
• The notebook asks for the method of search. It should clarify (probably in the instructions before the notebook) what does this mean, and provide an example. Then sosen asks for a query, which may be seen as free text. An example would help too.
• The describe mechanic does not always return a table.
• I think the tf-idf score should be better explained before the notebook.