Convert docdock theme from submodule to native files and fix Hugo compatibility

themes/docdock/static/revealjs/plugin/multiplex/client.js

@@ -0,0 +1,13 @@
+(function() {
+	var multiplex = Reveal.getConfig().multiplex;
+	var socketId = multiplex.id;
+	var socket = io.connect(multiplex.url);
+
+	socket.on(multiplex.id, function(data) {
+		// ignore data from sockets that aren't ours
+		if (data.socketId !== socketId) { return; }
+		if( window.location.host === 'localhost:1947' ) return;
+
+		Reveal.setState(data.state);
+	});
+}());