Add Google Calendar sidebar module

Now the website does not need to have another calendar to maintain.
Shows a 270x300 agenda with all extra options disabled since the sidebar
is small.
Uses .Site.Params.calendarId to identify the calendar.

Signed-off-by: Ethan Madison <ethan@ethanmad.com>

layouts/partials/sidebar-single.html

@@ -14,5 +14,15 @@
             {{ with .Site.Params.practiceTimes.saturday }}<strong>Saturday</strong>: {{ . }}<br>{{ end }}
         {{ end }}
 	</div>
+
+    {{ if (isset .Site.Params "practiceTimes") and (isset .Site.Params "calendarId") }}
+    <br><br>
+    {{ end }}
+
+    {{ with .Site.Params.calendarId }}
+    <div class="sidebar-module">
+        <h4 class="sidebar-heading">Calendar</h4>   </div>
+        <iframe src="https://calendar.google.com/calendar/embed?showTitle=0&amp;showNav=0&amp;showDate=0&amp;showPrint=0&amp;showTabs=0&amp;showCalendars=0&amp;showTz=0&amp;mode=AGENDA&amp;height=300&amp;wkst=1&amp;bgcolor=%23ffffff&amp;src={{ . }}&amp;color=%232952A3&amp;ctz=America%2FNew_York" style="border-width:0" width="270" height="300" frameborder="0" scrolling="no"></iframe>
+    {{ end }}
 	</div>
 </div><!-- /.doc-sidebar -->