Update section on circuit library

[Cryoris]

URL, if applicable

https://docs.quantum.ibm.com/guides/circuit-library

Describe the new content you are requesting.

We should update the circuit library guide, accompanying the updates we're shipping in Qiskit 1.3; the new, fast functions and the abstract construction via gates. I'm happy to provide a draft, the QDC talk material should be re-usable.

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

I will write a draft of the proposed content

[Eric-Arellano]

Awesome! The new gates already exist in API docs under /api/qiskit/dev - feel free to link to those while you're iterating on this. If you do, please put a reminder in your PR description that we need to rewrite those to be qiskit without /dev once 1.3 goes live.