Add example near-Clifford circuit simulators with links

[bdg221]

Fixes #2241

In order to make the documentation more helpful, we should provide users with examples of near-Clifford circuit simulators that are necessary when using CDR at scale. In particular, this should happen in the CDR guide.

This PR includes the changes that takes the documentation from:
To use CDR at scale, an efficient near-Clifford circuit simulator must be specified. In this example, the circuit is small enough to use any classical simulator, and we use the same density matrix simulator as above but without noise.

To the new version:
To use CDR at scale, an efficient near-Clifford circuit simulator must be specified. Two examples of efficient near-Clifford circuit simulators are Qrack with the stabilizer hybrid (Clifford+Rz) and IBM's extended stabilizer simulator.

In this example, the circuit is small enough to use any classical simulator, and we use the same density matrix simulator as above but without noise.

License

• I license this contribution under the terms of the GNU GPL, version 3 and grant Unitary Fund the right to provide additional permissions as described in section 7 of the GNU GPL, version 3.

Before opening the PR, please ensure you have completed the following where appropriate.

• I added unit tests for new code.
• I used type hints in function signatures.
• I used Google-style docstrings for functions.
• I updated the documentation where relevant.
• Added myself / the copyright holder to the AUTHORS file

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 98.32%. Comparing base (aefc5ce) to head (d5ff900).

Additional details and impacted files

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##             main    #2367   +/-   ##
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  Coverage   98.32%   98.32%           
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  Files          87       87           
  Lines        4059     4059           
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  Hits         3991     3991           
  Misses         68       68           

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