update-sites/stats: help the final label be shown

Dygraphs appears to treat the end of the active time range as an
exclusive bound for the purpose of deciding whether each tick's label
should be rendered. We want the final tick to be rendered even though
it describes the final data point in the chart's initial data range.

Author: ctrueden

_pages/update-sites/stats.md

@@ -552,6 +552,14 @@ Note:
         chartConfig.ylabel = yLabel;
       }
 
+      // Extend the date window slightly to ensure final tick label is within bounds
+      if (data && data.length > 0) {
+        chartConfig.dateWindow = [
+          data[0][0].getTime(),
+          data[data.length-1][0].getTime() + 1 // Add a sliver of time
+        ];
+      }
+
       new Dygraph(document.getElementById("stats-chart"), data, chartConfig);
 
     } catch (error) {