Add support for FXML files.

lib/linguist/languages.yml

@@ -3120,6 +3120,7 @@ XML:
   - .dll.config
   - .filters
   - .fsproj
+  - .fxml
   - .glade
   - .grxml
   - .ivy

samples/XML/FXMLSample.fxml

@@ -0,0 +1,30 @@
+<?xml version="1.0" encoding="UTF-8"?>
+
+<?import javafx.geometry.*?>
+<?import javafx.scene.control.*?>
+<?import java.lang.*?>
+<?import javafx.scene.layout.*?>
+
+
+<BorderPane maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="400.0" prefWidth="600.0" xmlns="http://javafx.com/javafx/8" xmlns:fx="http://javafx.com/fxml/1">
+   <center>
+      <TableView prefHeight="200.0" prefWidth="200.0" BorderPane.alignment="CENTER">
+        <columns>
+          <TableColumn prefWidth="114.0" text="Column 1" />
+          <TableColumn minWidth="0.0" prefWidth="243.0" text="Column 2" />
+          <TableColumn prefWidth="214.0" text="Column 3" />
+        </columns>
+      </TableView>
+   </center>
+   <bottom>
+      <HBox alignment="CENTER_RIGHT" prefWidth="200.0" spacing="10.0" BorderPane.alignment="CENTER">
+         <children>
+            <Button mnemonicParsing="false" text="Button">
+               <HBox.margin>
+                  <Insets bottom="10.0" left="10.0" right="10.0" top="10.0" />
+               </HBox.margin>
+            </Button>
+         </children>
+      </HBox>
+   </bottom>
+</BorderPane>