Add a 'git-publish' profile

The `git-publish`[1] tool is a wrapper around `git-format-patch` and
`git-send-email`.  It's a handy tool that automates some of the tedious
aspects of patch submission.

We've added it for the main libguestfs repo here[1].

[1] libguestfs/libguestfs@8487e906d

Signed-off-by: Kashyap Chamarthy <[email protected]>

Author: kashyapc

.gitpublish

@@ -0,0 +1,3 @@
+[gitpublishprofile "default"]
+base = master
+to = [email protected]