updated readme

Author: vlabatut

README.md

@@ -15,7 +15,7 @@ MedievalAvignon is free software: you can redistribute it and/or modify it under
 
 If you use this source code or the associated dataset, please cite reference [[F'22](#references)].
 
-![MedievalAvignonNet](/out/graph_both.svg)
+![MedievalAvignonNet](/out/graph_both.jpg)
 
 # Description
 This set of R scripts aims at extracting and analyzing confront networks extracted from raw historical tables. It does the following: