Add QuTiP option to Donate page

[nathanshammah]

There's been a request from the QuTiP team for UF to accept online donation for QuTiP as its affiliated project. This can be done easily by adding a special donate field on the "donate" page. It requires:

• Adding new text to the donate page on QuTiP
• Setting up a new special PayPal link just for QuTiP

[beecastanon]

@nathanshammah we're waiting on QuTiP to send along donation levels, which they noted they would provide us with this week. The PayPal link will be just for QuTiP, but as a reminder needs to note that the money is going to UF. Will circle back when we have the levels.

[veena-vee989]

Do we still need to add the paypal link to the website, or can I mark this as complete @beecastanon?