Relates to #8965
* Fixes offlinedocs that broke from change in feat(coderd/healthcheck): add access URL error codes and healthcheck doc #10915 by removing the offending anchor links from the page subheadings.
* Makes offlinedocs also conditional on changes to docs
Relates to #8965
- Added error codes for separate code paths in health checks
- Prefixed errors and warnings with error code prefixes
- Added a docs page with details on each code, cause and solution
Co-authored-by: Muhammad Atif Ali <atif@coder.com>