Format README.md usage section with code block

README.md

@@ -13,10 +13,10 @@ Recommended model: ``gemma3-translator:4b``
 - Saves output as a new `.md` file
 
 ## Usage
-
+```
 bash
 python text-to-markdown.py input.txt
-
+```
 
 ## License
 This project is licensed under the MIT License.