feat(textRun): implemented footnote references on the text run element

src/file/paragraph/run/text-run.ts

@@ -1,3 +1,4 @@
+import { FootnoteReferenceRun } from "file/footnotes/footnote/run/reference-run";
 import { IRunOptions, Run } from "./run";
 import { Text } from "./run-components/text";
 
@@ -16,4 +17,9 @@ export class TextRun extends Run {
         super(options);
         this.root.push(new Text(options.text));
     }
+
+    public referenceFootnote(id: number): TextRun {
+        this.root.push(new FootnoteReferenceRun(id));
+        return this;
+    }
 }