rename chapter 11

Author: forax

README.md

@@ -17,24 +17,25 @@ All the codes run with Java 14 with the preview features enabled.
 7. [lambda.md](guide/chapter08-lambda.md)
 8. [list_and_map.md](guide/chapter09-list_and_map.md)
 9. [string_formatting.md](guide/chapter10-string_formatting.md)
-10. [encapsulation.md](guide/chapter11-encapsulation.md)
+10. [class_and_encapsulation.md](guide/chapter11-class_and_encapsulation.md)
 11. [equals_hashCode_toString.md](guide/chapter12-equals_hashCode_toString.md)
 12. [contract.md](guide/chapter13-contract.md)
 13. [modifiable_vs_mutable.md](guide/chapter13-modifiable_vs_mutable.md)
 14. [null_and_optional.md](guide/chapter14-null_and_optional.md)
 15. [inheritance.md](guide/chapter15-inheritance.md)
 16. [exception.md](guide/chapter16-exception.md)
 17. [enum.md](guide/chapter17-enum.md)
-18. [internal_classes.md](guide/chapter18-internal_classes.md)
-19. [implementing_interface.md](guide/chapter19-implementing_interface.md)
-20. [generics.md](guide/chapter20-generics.md)
-21. [wrapper.md](guide/chapter21-wrapper.md)
-22. [variance.md](guide/chapter22-variance.md)
-23. [limitation_of_generics.md](guide/chapter23-limitation_of_generics.md)
-24. [stream.md](guide/chapter25-stream.md)
-25. [collector.md](guide/chapter26-collector.md)
-26. [data_structure.md](guide/chapter30-data_structure.md)
-27. [sort.md](guide/chapter31-sort.md)
+18. [nested_classes.md](guide/chapter18-nested_classes.md)
+19. [array.md](guide/chapter19-array.md)
+20. [implementing_interface.md](guide/chapter19-implementing_interface.md)
+21. [generics.md](guide/chapter20-generics.md)
+22. [wrapper.md](guide/chapter21-wrapper.md)
+23. [variance.md](guide/chapter22-variance.md)
+24. [limitation_of_generics.md](guide/chapter23-limitation_of_generics.md)
+25. [stream.md](guide/chapter25-stream.md)
+26. [collector.md](guide/chapter26-collector.md)
+27. [data_structure.md](guide/chapter30-data_structure.md)
+28. [sort.md](guide/chapter31-sort.md)
 
 
 ## Using Java Shell (jshell)