Fixed a formatting mistake.

README.md

@@ -1,6 +1,6 @@
 # [fiction-dl](https://github.com/DreamCobbler/fiction-dl) (*1.2.0*)
 
-![Screenshot](/Screenshot.jpeg?raw=true)
+![Screenshot](/Screenshot.png?raw=true)
 
 **fiction-dl** is a command-line utility used for downloading works of fiction from the web, formatting them and storing them in a few common file formats. It requires a [Python](https://www.python.org/) interpreter installed, version 3.8 or higher.