[PATCH] internals: document that "branches" is a legacy command

[Yuya Nishihara]

On Wed, 3 May 2017 22:13:17 +0100, Siddharth Agarwal wrote:
> On 5/3/17 22:07, Siddharth Agarwal wrote:
> > # HG changeset patch
> > # User Siddharth Agarwal <sid0 at fb.com>
> > # Date 1493845634 25200
> > #      Wed May 03 14:07:14 2017 -0700
> > # Node ID 7e90b9553a02ef30fd289736cfb559c83b6766e2
> > # Parent  8ac7ac714e922fd34abe9f5a16fcf018c8b12abc
> > internals: document that "branches" is a legacy command
> 
> As martinvonz helpfully pointed out on IRC, this should read "legacy 
> wire command". Whoops!

Updated the commit summary and queued, thanks.