Going forward we'll only maintain doc branches for maintained streams of PuppetDB (currently that's 5.2.x, 6.0.x and 6.3.x). The docs page will also feature a "latest" version, which is the most recent y release. As a result of currently separating release notes via y release, some release notes (such as those for 6.1.0 and 6.2.0) would not be visible on the docs page. Combining these to x version will solve that issue.