Fix broken docs links

[coruscating]

Qiskit 0.45.2 removed all tutorials, so intersphinx linking no longer works and breaks the docs build. This PR updates Qiskit tutorial links to 1XP pages that give the corresponding information and also fixes a broken internal link.

[wshanks]

Looks good! "IBM Quantum Documentation's introductory guides" just links to IBM Quantum Documentation so maybe the link should just be on that part but it is clear enough.

[coruscating]

@wshanks Oh yeah, that would probably be clearer. I was also trying to figure out if there's a way to just link to the "Start/Build/Transpile/Verify/Run" series of pages without including the API reference and tutorials, which are more advanced than the old intro tutorials. @Eric-Arellano is there a page for just these introductory guides (are these guides?) or what would be a clear way to refer to them from external docs?

[Eric-Arellano]

I was also trying to figure out if there's a way to just link to the "Start/Build/Transpile/Verify/Run" series of pages without including the API reference and tutorials, which are more advanced than the old intro tutorials

I'm not sure I follow. You could link to each individual index page like /start and /transpile? But in general the home page is probably best. I would assume your average user knows they don't need to read the API docs cover-to-cover.

It's good you only say "familiarity with" to make it clear they don't need to have deeply read every single docs page.

[coruscating]

@Eric-Arellano Yeah, I was just wondering if there's another portal on 1XP that only has the introductory series since I thought linking to the pages individually would be too fussy. I'll just continue to link to the home page then.