update README.md

Author: n1nj4t4nuk1

README.md

@@ -1,3 +1,23 @@
 # Python Value-Objects
 
-A collection of Value Objects to save time by generalizing types and format validations.
+A collection of Value Objects to save time by generalizing types and format validations.
+
+* [Value-objects](#value-objects)
+  * [Numeric value-objects](#numeric-value-objects)
+    * [Int](#int)
+    * [Nullable Int](#nullable-int)
+  * [String value-objects](#string-value-objects)
+    * [String](#string)
+
+
+# Value-objects
+
+## Numeric value-objects
+
+### Int
+
+### Nullable Int
+
+## String value-objects
+
+### String