CG: Add comment about git-cl editor

CG: Add comment about git-cl editor

git-cl fires either the editor specified by the EDITOR environment
variable or vi if EDITOR isn't defined.
Commit mentions this in the CG

[uliska, 2013-12-12 11:11:45]

Describing the solution for my problem when using git-cl for the first time

[uliska, 2013-12-12 11:40:00]

On 2013/12/12 11:11:45, uliska wrote:
> Describing the solution for my problem when using git-cl for the first time

Actually I'm not sure if @var is the right one here?

[Devon Schudy, 2013-12-15 23:58:45]

uliska wrote:
> Actually I'm not sure if @var is the right one here?

The Texinfo documentation says it should be @code: “Do not use @var for the
names of normal variables in computer programs. These are specific names, so
@code is correct for them”.

[uliska, 2013-12-16 06:11:23]

Use correct texinfo command