Add math run and fraction

src/file/paragraph/math/math.ts

@@ -0,0 +1,19 @@
+// http://www.datypic.com/sc/ooxml/e-m_oMath-1.html
+import { XmlComponent } from "file/xml-components";
+
+import { MathFraction } from "./fraction";
+import { MathRun } from "./math-run";
+
+export interface IMathOptions {
+    readonly children: Array<MathRun | MathFraction>;
+}
+
+export class Math extends XmlComponent {
+    constructor(readonly options: IMathOptions) {
+        super("m:oMath");
+
+        for (const child of options.children) {
+            this.root.push(child);
+        }
+    }
+}