[Feature] Add third level headers to the doc page table of contents to improve navigation

[UnchartedSediment]

Can you please consider adding the third level of headings in the docs pages to the table of contents, some of the larger pages are also the ones I reference the most like Start-ADTProcess and Start-ADTMsiProcess, being able to navigate directly to the necessary parameter would significantly improve the end user experience for the site on the longer pages.

Example of this in action from the Docusaurus Powershell site

website/docusaurus.config.js

Lines 127 to 130 in 24c410d

	tableOfContents: {
	minHeadingLevel: 2,
	maxHeadingLevel: 2,
	},

[DanGough]

It appears we currently have an issue with some of the PowerShell help text being converted to headers when they shouldn't be - so increasing the maxHeadingLevel to 3 results in a lot of unwanted text in the there:

If we get that resolved (it's converted automatically by PlatyPS), we may be able to action this request.