Add some more explanation to README

Author: coffeenotfound

README.md

@@ -10,7 +10,8 @@ imported with `File > Import... > Run/Debug > Launch Configurations`, but note t
 not rebuild the mod.
 
 When editing resources make sure to refresh the project (`The project (Right click) > Refresh`), otherwise
-the changes may not be visible in game.
+the changes may not be visible in game. This is because when starting from a non-Gradle start in Eclipse
+the resources from the `bin` folder are used which gets updated by Eclipse, not Gradle.
 
 # Building
 Building is simply done via `./gradlew build`.