As we are using the static file for showing versions in the drop-down
this would be outdated with each new release, so use it from the main
branch, with the assumption that it would always be up-to-date.
- Ran linkcheck on the built docs and fixed broken links
- Added exceptions for private, anchors, and server errors
that may come up when we run the linkcheck in CI.
- Also ignore self-referential GitHub links with commit hashes
- Fixed links on the insights page
- Converted some links to use the anchored format
- Fixes#1319