Update README.md

Author: Enet4

encoding/README.md

@@ -1,6 +1,6 @@
 # DICOM-rs encoding library
 
 [![CratesIO](https://img.shields.io/crates/v/dicom-encoding.svg)](https://crates.io/crates/dicom-encoding)
-[![Documentation](https://docs.rs/dicom-core/badge.svg)](https://docs.rs/dicom-core)
+[![Documentation](https://docs.rs/dicom-encoding/badge.svg)](https://docs.rs/dicom-encoding)
 
 This sub-project provides DICOM data encoding and decoding primitives.