serve notes/multiple index document as html (closes #470)

plugin/multiplex/index.js

@@ -30,6 +30,7 @@ app.configure(function() {
 });
 
 app.get("/", function(req, res) {
+	res.writeHead(200, {'Content-Type': 'text/html'})
 	fs.createReadStream(opts.baseDir + '/index.html').pipe(res);
 });
 

plugin/notes-server/index.js

@@ -30,6 +30,7 @@ app.configure(function() {
 });
 
 app.get("/", function(req, res) {
+	res.writeHead(200, {'Content-Type': 'text/html'})
 	fs.createReadStream(opts.baseDir + '/index.html').pipe(res);
 });