Add missing Circuit methods to API docs

[CalMacCQ]

Description

Adding some more Circuit methods that were left out of the API docs.

['add_circbox_regwise', 'AAMS', 'GPI', 'add_circbox_with_regmap', 'GPI2', 'add_termsequencebox']

These were found using the check_circuit_class_docs.py. script. Unfortunately haven't been able to get the sphinx coverage extension to work reliably to check all of the docs.

Related issues

Please mention any github issues addressed by this PR.

Checklist

• I have performed a self-review of my code.
• I have commented hard-to-understand parts of my code.
• I have made corresponding changes to the public API documentation.
• I have added tests that prove my fix is effective or that my feature works.
• I have updated the changelog with any user-facing changes.

[cqc-alec]

Doesn't have to be in this PR, but maybe these should be in alphabetical order to make them easier to find?

[CalMacCQ]

The order I opted for was to have similar gates grouped together rather than alphabetical

e.g.

   .. automethod:: CRy

   .. automethod:: CRz

   .. automethod:: CU1

   .. automethod:: CU3

Alphabetical ordering would mean that Circuit.AAMS would be at the top and the more commonly used Circuit.Z would be at the bottom.

Maybe alphabetical is better, not sure.