[m-rev.] for review: Add synonyms for digraph sc, tc, rtc.

[Julien Fischer]

On Thu, 19 Jan 2023, Peter Wang wrote:

> library/digraph.m:
>    Add non-abbreviated synonyms for digraph.sc, digraph.tc, and
>    digraph.rtc.
>
> NEWS:
>    Announce additions.

That's fine -- thanks for that.

Julien.