plugins/caldav: add missing event.html template

plugins/caldav/public/event.html

@@ -0,0 +1,20 @@
+{{template "head.html"}}
+
+<h1>koushin</h1>
+
+<p>
+  <a href="/calendar">Back</a>
+</p>
+
+{{$event := index .Event.Data.Events 0}}
+
+<h2>Event: {{$event.Summary}}</h2>
+
+<ul>
+  <li><strong>Start date</strong>: {{$event.StartDate | formatdate}}</li>
+  <li><strong>End date</strong>: {{$event.EndDate | formatdate}}</li>
+</ul>
+
+<pre>{{$event.Description}}</pre>
+
+{{template "foot.html"}}