cmd/go: documentation at golang.org for cmd/go has confusing formatting [1.16 backport]

[gopherbot]

@jayconrod requested issue #44846 to be considered for backport to the next 1.16 minor release.

@gopherbot Please backport to 1.16. This is a fix for documentation that will be current for several more months.

[dmitshur]

Approving as a documentation fix. Only Go 1.16 needs this backport.

[gopherbot]

Change https://golang.org/cl/301429 mentions this issue: [release-branch.go1.16] cmd/go: fix godoc formatting for text from 'go help install'

[gopherbot]

Closed by merging f39c4de to release-branch.go1.16.