Bug#908291: developers-reference, section 5.11.4: Add a note on versioning scheme when reverting an NMU

[Joseph Herlant]

Hi Ian,

On Sun, Sep 9, 2018 at 7:39 AM Ian Jackson
<ijack...@chiark.greenend.org.uk> wrote:
> Maybe adding a link or xref to policy 5.6.12.1 would be helpful.

Good point, thanks! I updated the MR to include the reference to the policy.

Joseph