fix image url for marketplace

README.md

@@ -12,7 +12,7 @@ The plug-in comes with a wealth of features to make your programming experience
 - Open projects and scenes in Godot from VScode
 - Ctrl click on a variable or method call to jump to its definition (_new in 0.1.3_)
 
-![Showing the documentation on hover feature](img/documentation-on-hover.png "Method definition and docs on hover")
+![Showing the documentation on hover feature](https://raw.githubusercontent.com/GodotExplorer/godot-tools/master/img/documentation-on-hover.png "Method definition and docs on hover")
 
 ## Available commands