demo: shrink registered-users chart to the 1160px slide content width

Change-Id: I3bda10378198acb8b8220b19ab64940c7c51b251
diff --git a/examples/ids.Rmd b/examples/ids.Rmd
index 3339b44..9fca102 100644
--- a/examples/ids.Rmd
+++ b/examples/ids.Rmd
@@ -84,7 +84,7 @@
   hc_yAxis(title = list(text = "")) %>%
   hc_xAxis(title = list(text = "")) %>%
   hc_legend(element_blank()) %>%
-  hc_size(height = 500, width = 1260)
+  hc_size(height = 500, width = 1160)
 hc
 ```