Merge branch 'master' into 1.15

src/main/java/carpet/script/value/MapValue.java

@@ -85,7 +85,8 @@ public class MapValue extends AbstractListValue implements ContainerValueInterfa
     @Override
     public Value add(Value o)
     {
-        throw new InternalExpressionException("Cannot add to a map value");
+        append(o);
+        return this;
     }
 
     @Override