Update README.md

README.md

@@ -3,6 +3,13 @@
 [![GoReportCard](https://goreportcard.com/badge/github.com/rekby/objwalker)](https://goreportcard.com/report/github.com/rekby/objwalker)
 
 Deep walk by object with reflection. With recursive loop protection.
+
+WalkInfo - struct, send as argument to callback function include:
+
+```Value``` - reflection.Value object for read/manipulate with it.
+```InternalStructSize``` - size of internal structs (slice/string header, map struct at first level, ...)
+```DataPointer``` - direct pointer to underly data, for example - pointer to bytes under string, ot pointer to data under slice. It is danger to manipulate it, but can userful for example for compare objects.
+
 ```golang
 	type S struct {
 		Val1  int