Improve page table of contents settings for Qiskit release notes

[Eric-Arellano]

We set that release notes should only show h2 headers:

documentation/scripts/lib/api/addFrontMatter.ts

Lines 41 to 52 in 8ca657f

	} else if (result.isReleaseNotes) {
	const versionStr = pkg.hasSeparateReleaseNotes
	? ` ${pkg.versionWithoutPatch}`
	: "";
	const descriptionSuffix = pkg.hasSeparateReleaseNotes
	? `in ${pkg.title}${versionStr}`
	: `to ${pkg.title}`;
	result.markdown = `---
	title: ${pkg.title}${versionStr} release notes
	description: Changes made ${descriptionSuffix}
	in_page_toc_max_heading_level: 2
	---

(Note that in_page_toc_min_heading_level is set to 2 by default)

That setting to only show h2 works great for Runtime and Provider. Their release notes are very small in each release, and they have a lot of releases all on the same page.

But this is a bad setting for Qiskit, which has a dedicated release note per version:

• For Qiskit <=0.44 with its metapackage, we should be setting in_page_toc_max_heading_level to 4
• For Qiskit 0.45+, we should be using the default of in_page_toc_max_heading_level being 3, rather than setting it to 2.
  • Why is the setting only being applied for 0.45.md and not 0.46 and 1.0?