add license + examples (#3)

## Description
Added license file and changed the test

## Type of change
- [ ] Bug fix
- [ ] New feature
- [x] Documentation update
- [ ] Code refactoring

Author: CatarinaGamboa

latte-umbrella/LICENSE.md

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2025 University of Lisbon
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

latte-umbrella/src/main/java/examples/MyStackTest.java

@@ -3,21 +3,12 @@
 
 public class MyStackTest {
 
-        public static void main(String[] args) {
+    public static void main(String[] args) {
 
         // Define and initialize queues
-        LinkedList<Integer> qev1, qev2, qcv1, qcv2;
+        LinkedList<Integer> qev1;
         qev1 = new LinkedList<>();
-        qev2 = new LinkedList<>();
-        qcv1 = new LinkedList<>();
-        qcv2 = new LinkedList<>();
-
         qev1.add(100);
-        qev1.add(200);
-        qev1.add(300);
-        qev1.add(300);
-        qev1.add(300);
-        qev1.add(300);
 
         // Get an iterator for the queue
         Iterator<Integer> iterator = qev1.iterator();