Add dataset README with composition details

README.md

@@ -23,6 +23,7 @@ The dataset is a combination of data from multiple sources:
   - All positive arsenic skin lesion images are categorized into the `Arsenic` folder.
 - **Others Class:** 
   - Contains negative images from the arsenic data.
+  - Contains healthy skin images.
   - Contains all other skin diseases that had fewer than 100 images available in the DermaConIN and SkinDisNet datasets.
 
 ## Usage