Expose index page in left ToC for Runtime and Provider

[Eric-Arellano]

https://docs.quantum.ibm.com/api/qiskit-ibm-runtime and https://docs.quantum.ibm.com/api/qiskit-ibm-provider are orphan pages, meaning they don't show up in our left ToC. That is unlike Qiskit https://docs.quantum.ibm.com/api/qiskit, which is the index page.

Note that we only started surfacing the index pages for provider and runtime as part of #561. Runtime and Provider are interesting because they have an index page that lists all the modules, then a page about the top-level modules qiskit_ibm_runtime and qiskit_ibm_provider. This gets set up in

documentation/scripts/lib/api/specialCaseResults.ts

Lines 27 to 28 in 2a2c40a

	.replace(/(?<=^|\/)ibm-provider(?=#|$)/g, "index")
	.replace(/(?<=^|\/)ibm-runtime(?=#|$)/g, "index")

Qiskit is unlike Provider and Runtime, as it does have its index page https://docs.quantum.ibm.com/api/qiskit in the left sidebar. Qiskit does not have a page for all the imports of the top level module qiskit, it only has this index page. Note how qiskit/index has module metadata:

documentation/docs/api/qiskit/index.mdx

Lines 5 to 6 in 2a2c40a

	python_api_type: module
	python_api_name: qiskit

But Runtime and Provider do not:

documentation/docs/api/qiskit-ibm-runtime/index.mdx

Lines 1 to 5 in 2a2c40a

	---
	title: Qiskit Runtime IBM Client API Docs
	description: API documentation for qiskit-ibm-runtime
	---

Qiskit should stay the same, other than renaming "qiskit" to something like "Index" or "API index" as part of #1211. Meanwhile, Runtime and Provider need to add their index pages to the left ToC using the same name as Qiskit uses.