Outdated table of contents in index.ipynb

[claretgrace0801]

The table of contents in the index.ipynb does not match the table of contents on the qutip tutorials page.
Also, some of the links in the index.ipynb give a 404 error (for example - The noisy quantum device simulator under Pulse-level circuit simulation).

[BoxiLi]

Ah yes, I think when I update the qip-related notebooks in #138, I forgot to update index.ipynb. That notebook has been removed. The link on the tutorial page is more up-to-date.