
Automatic merge from submit-queue. If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>. Improve `horizontal.go` documentation **What this PR does / why we need it**: Resolve the remaining `golint` errors in the `pkg/controller/podautoscaler` package by improving the documentation in `horizontal.go`. Now all public methods have comments. **Special notes for your reviewer**: Re discussions in [this pr](https://github.com/kubernetes/kubernetes/pull/52238). **Release note**: ```release-note NONE ```