https://golang.org/cl/60590044 edited
doc.go without editing the file it is generated from.
The edit was lost at the next mkdoc.sh.
Make the change in help.go and rerun mkdoc.sh.

Pointed out in the review of CL 68580043.

TBR=iant
CC=golang-codereviews
https://golang.org/cl/88760043