Add "Add Calendar" page

There's now a tutorial linked from Schedule on adding the calendar.
Signed-off-by: Ethan Madison <ethan@ethanmad.com>

content/add-calendar.md

++++
+categories = ["general"]
+date = "2016-07-03T16:25:56-07:00"
+tags = ["document"]
+title = "Add Google Calendar"
+
++++
+
+## To add the UMFC Google Calendar to yours:
+1. Click on the arrow next to "Other Calendars." 
+2. Select "Add a friend's calendar."
+3. Paste in <pre>eub272o1l4u2jvmm9grh0bv074@group.calendar.google.com</pre>
+4. Click "Add."
+
+![](../img/add-calendar.jpg)

content/schedule.md

@@ -7,5 +7,5 @@ noshowdate = true
 
 +++
 
-<div class="alert alert-info" role="alert">This calendar is regularly updated with practice times, competitions, and other events.</div>
+<div class="alert alert-info" role="alert">This calendar is regularly updated with practice times, competitions, and other events. <a href="../add-calendar" class="alert-link">Add it to your calendar</a> to stay updated.</div>
 <iframe src="https://calendar.google.com/calendar/embed?showTitle=0&amp;showPrint=0&amp;showCalendars=0&amp;height=600&amp;wkst=1&amp;bgcolor=%23FFFFFF&amp;src=eub272o1l4u2jvmm9grh0bv074%40group.calendar.google.com&amp;color=%232952A3&amp;ctz=America%2FNew_York" style="border-width:0" width="100%" height="600" frameborder="0" scrolling="no"></iframe>