added a title for 3.3.1

Author: habibasorour

source/ch3_javadatatypes.ptx

@@ -460,7 +460,8 @@ void main() {
  In fact, this is the first example of another big difference between Java and Python. Java does not support any operator overloading. Table 3 maps common Python string operations to their Java counterparts. For the examples shown in the table we will use a string variable called “str” 
         </p>
 
-        <table>
+        <table> 
+        <title> Comparison of common string operations in Python and Java. </title> 
             <tabular>
                 <row header="yes">
                     <cell> Python </cell>