Add styles to footnote

src/file/footnotes/footnote/run/footnote-ref-run.ts

@@ -0,0 +1,11 @@
+import { Run } from "file/paragraph";
+import { FootnoteRef } from "./footnote-ref";
+
+export class FootnoteRefRun extends Run {
+    constructor() {
+        super();
+
+        this.style("FootnoteReference");
+        this.root.push(new FootnoteRef());
+    }
+}

src/file/footnotes/footnote/run/footnote-ref.ts

@@ -0,0 +1,7 @@
+import { XmlComponent } from "file/xml-components";
+
+export class FootnoteRef extends XmlComponent {
+    constructor() {
+        super("w:footnoteRef");
+    }
+}