Tutorial: Composing techniques: Pauli Twirling and Zero Noise Extrapolation

[cosenal]

In the same way we have a tutorial for REM+ZNE and one for DDD+ZNE, we want to create one about composition of Pauli Twirling (PT) and ZNE.

This would be an exploratory jupyter notebook in the Tutorial secions of Mitiq docs.

Ideally, the example would show that error(PT + ZNE) < error(PT) < error(ZNE)

[purva-thakre]

When this tutorial is added, please link it on the main landing page of the PT user guide.

Currently, at the bottom of this page, we are linking all the examples we have in the documentation. For most user guides, we tend to link a tutorial for that technique if we have it (main landing page of REM).