Add dev summit notes for 2017 & 2018

Signed-off-by: Richard Hartmann <richih@richih.org>

content/community.html

@@ -52,6 +52,17 @@ title: Community
       <a href="https://groups.google.com/forum/#!forum/prometheus-developers">prometheus-developers</a> – for discussions around Prometheus development
     </p>
 
+    <h1>Development summits</h1>
+    <p>
+      We strive to be as open as public as public. Technical discussions happen on the development list, our in-person meeting notes are public, and we have public calls.
+    </p>
+    <p>
+      <a href=""https://docs.google.com/document/d/1DaHFao0saZ3MDt9yuuxLaCQg8WGadO8s44i3cxSARcM/edit#heading=h.bbvw42ndm0nb>2017 dev summit notes</a>
+    </p>
+    <p>
+      <a href=""https://docs.google.com/document/d/1-C5PycocOZEVIPrmM1hn8fBelShqtqiAmFptoG4yK70/edit>2018 dev summit notes</a>
+    </p>
+
     <h1>Project Governance</h1>
     <p>
       Prometheus is an independent open-source project and not controlled by