Update Candidate Guide and RAD FAQ for guidance search

[dorothyyeager]

Summary

What we are after:
_To solve the problem of the Candidate Guide not being discovered by the guidance search, we've learned that we need to upload an optimized version that is less than 15MB. @jjonesfec is awesome and made us one.

OGC wants us to rename the RAD FAQ URL so we're doing that too._

Related issues

#4053 - where we put in a best bet to solve the issue but that's just a workaround
#4054 - updating sitemap

Completion criteria

• New guide version is uploaded to CMS
• Wagtail site map is updated
• Github repo is updated
• New file uploaded to Content team folder in instructions

Tech steps or considerations (optional)

See our guidance for how to do this: https://docs.google.com/document/d/1hfvlYhGVNF0Km5vrAYtJak2cdAYLYQPbiPUfLxbRN1E/edit#heading=h.83p10qypinz4

It would be good to demo for content team so they see process.

Future work

We'll need to do this for the RAD FAQ soon too.

Also this is a lot of work; and we have this automation ticket we should consider prioritizing: #3804