Redeploy "Documentation: Update information regarding our rate limits"

[beautifulentropy]

This document is a revised version of the existing rate limits documentation. The goals of this new version are:

• Re-organizes the page visually and structurally to make it easier use as a reference
• Enables easy "deep-linking", each rate limits error message can now link directly to the limit that has been exceeded.
• Consolidates three additional pages added in 2021: Duplicate Certificate, Failed Validation, and Accounts per IP Address).
• Clarifies which limits are enforced globally and explains exactly what that means.
• Clarifies which limits can and cannot be overridden.
• Clarifies how limit exemptions apply when renewing certificates.
• Explains that our limits are now evaluated using a leaky bucket algorithm instead of a sliding window.
• Eliminates the Pending Authorizations limit, as it no longer exists in our updated rate limits implementation.
• Introduces a section covering more consistent format of our new rate limit error messages, including:
  • the new “retry after” timestamp, and
  • the new Retry-After headers we've added to each rate limit error.
• More consistent usage of terminology:
  • Uses "hostname" instead of "domain", "name", or "FQDN".
  • Uses "registered domain" instead of "domain" or "domain name".

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These changes were approved in #1754 and reverted in #1755.

Do not merge this until letsencrypt/boulder#7767 is deployed to production.