Improve titles of tutorials

[nathanshammah]

Issue Description

The titles of the tutorials could be improved. It is hard to understand right now the difference between tutorials. I propose to have some sort of classification, with a common structure. Like: {technique - topic - front end}, e.g., Using ZNE for H2 calculation with Cirq... or something similar.

[nickdgardner]

Definitely agree! Also, the markdown headings in some examples could be improved/made more consistent. For example Mirror circuit benchmark improved with zero-noise extrapolation on AWS Braket has top-level heading "Mitiq with Braket", which is not specific enough.

I'll keep these issues in mind as I finish adapting the Variational circuit mitigation with zero-noise extrapolation example to other frontends, and I can post a list of candidate changes here as a starting point.

[andreamari]

Thanks @nickdgardner!