Doc example using missing function count_multi_qubit_gates_qiskit

[bachase]

Describe the bug
The user guide page in the documentation has example code for using ucc to compile a random Clifford circuit. When attempting to run the code, it fails on the line below due to an invalid import.

ucc/docs/source/user_guide.rst

Line 33 in 0ae8e4a

from ucc.benchmarks.utils import count_multi_qubit_gates_qiskit

To Reproduce

1. Runpip install ucc or git clone +pip install -e .
2. Copy and run the script linked above from the docs.
3. Get the error ModuleNotFoundError: No module named 'ucc.benchmarks'

Expected behavior
The script should run without error.

Additional context
I believe the import is just stale and should be updated to:

from benchmarks.scripts.common import count_multi_qubit_gates_qiskit

However, I'm unclear how the benchmarks module is meant to be distributed? Should it be a submodule of ucc versus a sibling?

If there continue to be example code in the docs, we can also consider testing that code as part of building the docs via doctest to ensure they continue to work.

[Misty-W]

Thanks for flagging this @bachase, well done!

I added the quick docs fix to PR #181 for some pre-launch cleanup of the docs.

Feel free to open an issue for making benchmarks a submodule of UCC. There may be a good reason why we didn't structure it that way in the first place, but I'm not remembering it at the moment.