It seems everyone agrees that `obslog` is not an intuitive name. There
was some discussion about alternatives in #3592 and on #4146. The
alternatives included `evolution`, `evolutionlog`, `evolog`,
`rewritelog`, `revlog`, and `changelog`. It seemed like
`evolution-log`/`evolog` was the most popular option. That also
matches the command's current help text ("Show how a change has
evolved over time").