doc: add sample cascade operations

doc/sample/Expressions.im

@@ -1,3 +1,4 @@
+
 y = 1 + 2 * 3 / 4 * 5 - 6 + 7 multiplyBy:2.
 z = w = 2 + 3 multiplyBy:2.
 x = (((1 + 2 * 3) multiplyBy:3) add: 5) + 2.
@@ -8,3 +9,18 @@ q = 10 squared squared.
 p1
     setAge:2 squared squared + 4 squared multiply(by:2 add:4 + 1 * 3)
     in:"mon" + "ths".
+
+M = xz multiply(by:3 add:2) squared.
+
+M = xz multiplyBy:3 add:2; yourself.
+
+x = OrderedCollection new
+	add: 2;
+	add: 4;
+	add: 6;
+	yourself.
+
+
+age = Person new(name:"John Doe" age:34)
+    setAge:144 inUnit:"months";
+    ageInMonths.