Define clear criteria for maintainer election

At the moment the election process for new maintainers is not clearly
defined:

* Is consensus reached if some of the maintainers do not vote?
* How long must a nomination stay open before a new maintainer can be
  accepted?

Make this clearer and require that:

* nominations stay open for at least 14 calendar days
* there are at least 5 positive votes
* there are no negative votes (during the 14 days)

Specifying this is important if we consider that we have some inactive
maintainers that likely don't take part in votes and in this situation
the maintainer election should not get stalled waiting on their votes.

If there are negative votes that are considered unjustified, the
engineering steering committee may get involved to decide whether the
new maintainer can be accepted anyway. Being able to escalate negative
votes to the ESC is important to avoid that a single maintainer can
block the whole process.

Bug: Issue 11069
Signed-off-by: Edwin Kempin <ekempin@google.com>
Change-Id: I888897f8f2ee5f35436acee8885d6ed994f750e2
diff --git a/Documentation/dev-roles.txt b/Documentation/dev-roles.txt
index b039489..9159b1c 100644
--- a/Documentation/dev-roles.txt
+++ b/Documentation/dev-roles.txt
@@ -207,10 +207,20 @@
   link:dev-processes.html#upgrading-libraries[Upgrading Libraries]
 * edit permissions on the Gerrit core projects
 
+[[maintainer-election]]
 Maintainers can nominate new maintainers by posting a nomination on the
-non-public maintainers mailing list. Nominations are approved by
-consensus among the maintainers. This means maintainers can veto a
-nomination.
+non-public maintainers mailing list. Nominations should stay open for
+at least 14 calendar days so that all maintainers have a chance to
+vote. To be approved as maintainer a minimum of 5 positive votes and no
+negative votes is required. This means if 5 positive votes without
+negative votes have been reached and 14 calendar days have passed, any
+maintainer can close the vote and welcome the new maintainer. Extending
+the voting period during holiday season or if there are not enough
+votes is possible, but the voting period should not exceed 1 month. If
+there are negative votes that are considered unjustified, the
+link:dev-processes.html#steering-committee[engineering steering
+committee] may get involved to decide whether the new maintainer can be
+accepted anyway.
 
 To become a maintainer, a link:#contributor[contributor] should have a
 history of deep technical contributions across different parts of the