Wallet API reference sidebar link issue

[alexandratran]

Since integrating the v2 OpenRPCParser, there's an issue with the sidebar linking from the Wallet API reference. To recreate:

1. Go to any method in the Wallet API reference.
2. Click "Introduction" at the top of the sidebar.
3. This takes you to docs.metamask.io/wallet/index/, which yields a "Page not found" error.
4. Refresh the page and it redirects to the proper Wallet introduction page.

We've tried adding an explicit redirect on the server-side (#1849) and client-side (#1853), but neither triggered the redirect when selecting from the Wallet API reference.