Re: docs-common Makefile.common,1.69,1.70

[Tommy Reynolds]

Uttered "Paul W. Frields" (pfrields) , spake thus:
> Add another phony alias "help" for better across-the-project adherence
> (q.v. Fedora Extras), plus it makes a weird kind of sense.
>
> -targets::
> +help targets::
>    @printf ${TFMT} 'targets' 'Outputs target summaries'
>    @printf ${TFMT} 'text' 'Same as "txt" target'

Good!  I was going to just s/targets/help/ anyway.