Add new example showing off how branches work

Signed-off-by: Alek Ratzloff <alekratz@gmail.com>

examples/branch.not

@@ -0,0 +1,13 @@
+check = fn(num) {
+    if num < 10 {
+        println("The number is pretty small.")
+    } elif num < 100 {
+        println("That number is getting pretty big.")
+    } el {
+        println("Whoa! That number is huge!")
+    }
+}
+
+check(1)
+check(10)
+check(100)