Revert "spec: document the underlying type of comparable"
Revert "spec: document the underlying type of comparable"

This reverts CL 380854.

Per the conluding discussions on #50791. A follow-up will
document `comparable` more thoroughly.

For #50791.

Change-Id: I15db9051784a012f713e28d725c3b8bbfeb40569
Reviewed-on: https://go-review.googlesource.com/c/go/+/381076
Trust: Robert Griesemer <a6752097faebf1f02d80107d77a9be009089afe3@golang.org>
Reviewed-by: Ian Lance Taylor <87e9c6d529889242b7e184afb632328636553ab4@golang.org>

CAFxX/go,CAFxX/go,golang/go,golang/go,CAFxX/go,cloudflare/go,nawawi/go,nawawi/go,cloudflare/go,golang/go,cloudflare/go,nawawi/go,golang/go,golang/go,nawawi/go,nawawi/go,cloudflare/go,CAFxX/go,nawawi/go,CAFxX/go,cloudflare/go,CAFxX/go,cloudflare/go,golang/go,golang/go,CAFxX/go,CAFxX/go,golang/go,cloudflare/go,nawawi/go,nawawi/go,cloudflare/go