Incorrect referencing to ipnewton_basics.ipynb in Nonlinear constrained optimization

[Dhuige]

There is an incorrect reference in Nonlinear constrained optimization to the ipnewton_basics.ipynb. Now you get the error 404 not found, see linked page

I can find it manually by searching for it on the github, but this is unpractical. Furthermore it has a slightly different address due to the "generated" folder

I reckon that this might occur in other pages as well, but this I have not checked.

[pkofod]

Okay, thank you for opening the issue. The docs had not been generated for quite a while, and I recently tried to bring it back to life. Apparently, I missed a few spots :)