Make fractions take math component

src/file/paragraph/math/fraction/math-fraction.ts

@@ -1,18 +1,19 @@
 import { XmlComponent } from "file/xml-components";
 
+import { MathComponent } from "../math-component";
 import { MathDenominator } from "./math-denominator";
 import { MathNumerator } from "./math-numerator";
 
 export interface IMathFractionOptions {
-    readonly numerator: MathNumerator;
-    readonly denominator: MathDenominator;
+    readonly numerator: MathComponent;
+    readonly denominator: MathComponent;
 }
 
 export class MathFraction extends XmlComponent {
     constructor(options: IMathFractionOptions) {
         super("m:f");
 
-        this.root.push(options.numerator);
-        this.root.push(options.denominator);
+        this.root.push(new MathNumerator(options.numerator));
+        this.root.push(new MathDenominator(options.denominator));
     }
 }