## Issue Addressed
NA
## Proposed Changes
Since we use the `rc` (release candidate) tag in our version strings, it seems consistent if we also use "release candidate" in the book rather than "pre-release".
Notably, Github adds a "pre-release" tag to release when we request. I think it's OK that Github uses that term whilst we consistently use "release candidate". Our docs indicate that the terms are interchangeable.
## Additional Info
I hope to use the new docs link in the `v2.1.0` release, so it would be nice if we can merge this soon 🙏
## Issue Addressed
NA
## Proposed Changes
When we released [`v1.4.0-rc.0`](https://github.com/sigp/lighthouse/releases/tag/v1.4.0-rc.0), we added a bunch of text about pre-releases. That information was useful, but somewhat hard to reference in future pre-releases.
This PR adds some docs to the book so whenever we do a pre-release we can point users to these docs for more info.
## Additional Info
NA
