Adding info on how to add a rust module to qiskit and make it available from within python

[sbrandhsn]

Summary

Details and comments

[qiskit-bot]

One or more of the following people are relevant to this code:

• @Qiskit/terra-core

[coveralls]

Pull Request Test Coverage Report for Build 10307442049

Warning: This coverage report may be inaccurate.

This pull request's base commit is no longer the HEAD commit of its target branch. This means it includes changes from outside the original pull request, including, potentially, unrelated coverage changes.

• For more information on this, see Tracking coverage changes with pull request builds.
• To avoid this issue with future PRs, see these Recommended CI Configurations.
• For a quick fix, rebase this PR at GitHub. Your next report should be accurate.

Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• 824 unchanged lines in 45 files lost coverage.
• Overall coverage increased (+0.002%) to 89.747%

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Files with Coverage Reduction	New Missed Lines	%
qiskit/compiler/transpiler.py	1	92.39%
qiskit/primitives/backend_sampler.py	1	98.86%
qiskit/primitives/statevector_sampler.py	1	99.08%
qiskit/primitives/backend_estimator_v2.py	2	98.29%
qiskit/providers/backend_compat.py	2	89.73%
qiskit/providers/fake_provider/fake_qasm_backend.py	2	95.56%
crates/accelerate/src/sabre/layout.rs	2	90.21%
qiskit/utils/deprecation.py	3	97.79%
qiskit/providers/models/backendproperties.py	3	95.36%
qiskit/primitives/statevector_estimator.py	3	94.44%

Totals
Change from base Build 10161705193:	0.002%
Covered Lines:	67373
Relevant Lines:	75070

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💛 - Coveralls

[raynelfss]

As someone who's had to figure out the ever changing ways of adding a PyO3 module to Qiskit, this is a much needed change. Thank you for working on this :)

I added a couple of comments about how to make this look a bit more readable and newcomer friendly, since it's mostly formatting nitpicks, I will leave them in comments for you to consider.

[sbrandhsn]

Looks great, thanks for the feedback! :-)

[raynelfss]

This looks good to me! However, I will not merge until @jakelishman takes a look, to see if this is explicit enough.

[jakelishman]

Thanks for this! It might help to drop a link to the relevant page of the PyO3 guide as well, so people can look in more detail.

[sbrandhsn]

Thanks for your feedback, I incorporated it in the latest commit.