docs...

Signed-off-by: Alex A. Naanou <alex.nanou@gmail.com>

README.md

@@ -49,6 +49,17 @@ Thus, care must be taken when serializing structures containing function.
 ### `partialDeepCopy(..)`
 
 
-
+## Format
+
+The output of `.serialize(..)` is a strict superset of standard JSON, 
+while the input format is a bit more relaxed than JSON in several details.
+
+Extensions to JSON:
+- Recursion
+- null types
+- BigInt
+- Map / Set
+- Function as code
+- Function as index