Move fxml location to resources

src/main/resources/fxml/Main.fxml

@@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="UTF-8"?>
+
+<?import java.net.*?>
+<?import javafx.geometry.*?>
+<?import javafx.scene.control.*?>
+<?import javafx.scene.layout.*?>
+<?import javafx.scene.text.*?>
+
+<VBox>
+    <children>
+        <Label text="Hello world!"/>
+    </children>
+</VBox>