This patch looks good to me.  If no one objects I'd like to merge it.

> +                                   (commit (channel-commit channel))
> +                                   (transformer hyperlink))
>    "Return a hyperlink for COMMIT in CHANNEL, using COMMIT as the hyperlink's
> -text.  The hyperlink links to a web view of COMMIT, when available."
> +text.  The hyperlink links to a web view of COMMIT, when available.
> +TRANSFORMER allows to control how the uri and text are."

uri -> URI.
"are displayed."
We should also tell the arguments TRANSFORMER takes.

Cheers!

-- 
Pierre Neidhardt
https://ambrevar.xyz/