Add math run and fraction

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

@@ -0,0 +1,18 @@
+import { XmlComponent } from "file/xml-components";
+
+import { MathDenominator } from "./math-denominator";
+import { MathNumerator } from "./math-numerator";
+
+export interface IMathFractionOptions {
+    readonly numerator: MathNumerator;
+    readonly denominator: MathDenominator;
+}
+
+export class MathFraction extends XmlComponent {
+    constructor(readonly options: IMathFractionOptions) {
+        super("m:f");
+
+        this.root.push(options.numerator);
+        this.root.push(options.denominator);
+    }
+}