Update tutorial

[rafacarrascosa]

A few files where renamed and the docs were not changed to reflect this.
In particular, the tutorial name a file parsing.py that does not exists because it was renamed to basic.py.
This error should be fixed and a review of the docs should be made.
Anybody is welcome to submit pull requests for this!

[iScienceLuvr]

This is the only error in the tutorials?

[rafacarrascosa]

As far as I know yes, but it would be a good thing to double check. If you spot anything let me know, I promise to be more responsive.

[ghost]

@rafacarrascosa created a PR for the same