When manually selecting the documentation for 0.3.0-rc2, a prominent warning is displayed at the top of the screen warning that the documentation is for an old version, namely, version 0.2.1. As 0.3.0-rc2 is newer, this doesn't make sense. It would be more sensible to include a warning that the selected documentation is for a pre-release version of zrepl.
https://zrepl.github.io/v0.3.0-rc2/