Propose content updates for "Domain pre-ready: Action required to activate domain" and "Expired 'DNS needed' domains - placed on hold" emails based on audit findings

[montecristo99]

Issue description

Based on the audit findings from #5203 , we need to finalize the changes we'll make to the "Domain pre-ready: Action required to activate domain" and "Expired "DNS needed" domains - placed on hold" emails in order to shorten the email content or, where needed, add or improve the directions we give to users.

Acceptance criteria

• Review the changes suggested in this doc.
• Update the "Domain pre-ready: Action required to activate domain" email with a link/blurb to the new "Setting up a .gov domain" page. Update the email doc here.
• Propose revisions to the content in the "Expired 'DNS needed' domains - placed on hold" email. Based on the product team's feedback in the proposal doc, we're looking for a shortened blurb about "on hold" status that still offers context for users, and then a link to the content we're adding to the FAQ. Update the email doc here.
• Share with design and product leads for feedback.
• Implement approved changes.

Additional context

No response

Links to other issues

• Audit "domain info" and "access and permission" emails for opportunities to move supporting content to get.gov #5203