add screenshot

README.md

@@ -1,5 +1,7 @@
 Golang implementation of a basic tree walk interpreter.
 
+<img src="./assets/screenshot.png" />
+
 Find the binaries for windows, linux and macos under the releases section.
 
 https://craftinginterpreters.com/

test.lox

@@ -52,4 +52,23 @@ fun makeCounter() {
 var counter = makeCounter();
 print counter(); // 1
 print counter(); // 2
-print counter(); // 3
+print counter(); // 3
+
+// Classes and inheritance
+class Animal {
+    speak() {
+        print "The animal makes a sound.";
+    }
+}
+
+class Dog < Animal {
+    speak() {
+        print "The dog barks.";
+    }
+}
+
+var animal = Animal();
+animal.speak(); // The animal makes a sound.
+
+var dog = Dog();
+dog.speak(); // The dog barks.