Update README.md

update asset reference

README.md

@@ -129,7 +129,7 @@ The plot shows the proportion of sites that have greater than 10% m6A methylatio
 
 Distances to downstream junctions are indicated on the right side of the plot. Distances to upstream junctions are indicated on the left side of the plot. 
 
-![Distribution of m6A sites around exon junctions](./assets/metajunction_m6A.png)
+![Distribution of m6A sites around exon junctions](./assets/metajunction_m6A.png?)
 
 More information about R2Dtool plots is available on the [R2Dtool Wiki](https://github.com/comprna/R2Dtool/wiki/Visualising-RNA-feature-distributions-with-R2Dtool).