Document that positive votes on design docs are sticky

For design docs it is often the case that people vote with Code-Review+1
to express their consent with the contents, but then these votes get
lost when minor issues such as nits, spelling mistakes, rephrasing,
adding some more points are addressed. Reviewers which already gave
their consent often don't come back after each iteration to re-apply
their Code-Review+1 vote, so that in the end it can look like there is
not much support for a design, while in fact many people agreed to it
(and just their Code-Review+1 votes are no longer visible). This makes
it more difficult to reason about approving a design by the ESC.

To improve this situation change I357351cd0 makes all positive
Code-Review votes in the homepage repo sticky. To prevent that
significant changes that are made by new patch sets stay unnoticed it is
the responsibility of the uploader to manually remove all positive votes
in this case. This change documents this.

Bug: Issue 12025
Signed-off-by: Edwin Kempin <ekempin@google.com>
Change-Id: I09177d70e1a19755cab228a83dacea7175cbdfa7
diff --git a/Documentation/dev-design-docs.txt b/Documentation/dev-design-docs.txt
index 5e3f7a9..e92b78a 100644
--- a/Documentation/dev-design-docs.txt
+++ b/Documentation/dev-design-docs.txt
@@ -98,6 +98,13 @@
 Everyone in the link:dev-roles.html[Gerrit community] is welcome to
 take part in the design review and comment on the design.
 
+Positive `Code-Review` votes on changes that add/modify design docs are
+sticky. This means any `Code-Review+1` and `Code-Review+2` vote is
+preserved when a new patch set is uploaded. If a new patch set makes
+significant changes, the uploader of the new patch set must start a new
+review round by removing all positive `Code-Review` votes from the
+change manually.
+
 Ideas for alternative solutions should be uploaded as a change that
 describes the solution (see link:#collaboration[above]).