Add controller and view example

When accessing http://localhost:8080/foo, the bar.html page is
rendered

Author: lidimayra

myapp/src/main/java/com/example/myapp/MyController.java

@@ -0,0 +1,12 @@
+package com.example.myapp;
+
+import org.springframework.stereotype.Controller;
+import org.springframework.web.bind.annotation.GetMapping;
+
+@Controller
+public class MyController {
+    @GetMapping("/foo")
+    public String index() {
+        return "bar";
+    }
+}

myapp/src/main/resources/templates/bar.html

@@ -0,0 +1 @@
+<p>FooBar</p>