Add explanatory material on error mitigation techniques

[kevinsung]

URL, if applicable

No response

Describe the new content you are requesting.

Techniques to document:

• Dynamical decoupling
• Measurement error mitigation
• Gate twirling
• Zero-noise extrapolation
• Probabilistic error amplification (?)
• Probabilistic error cancellation (?)

Some useful content for this can be found in the appendix of this notebook, which was the starting point of this PR, which didn't include that material in the final tutorial.

If this new content request is accepted, do you want to write the content?

I will write a draft of the proposed content

[javabster]

I'm thinking this piece would probably work well in the run section where we talk about the runtime options. If we can also include some code examples of how to set each type with runtime that would be great.

Also I think yes we should talk about PEA, and show people how to use it with the runtime experimental branch