Add Math Summation

src/file/paragraph/math/n-ary/math-accent-character.ts

@@ -0,0 +1,14 @@
+// http://www.datypic.com/sc/ooxml/e-m_chr-1.html
+import { XmlAttributeComponent, XmlComponent } from "file/xml-components";
+
+class MathAccentCharacterAttributes extends XmlAttributeComponent<{ readonly accent: string }> {
+    protected readonly xmlKeys = { accent: "m:val" };
+}
+
+export class MathAccentCharacter extends XmlComponent {
+    constructor(readonly accent: string) {
+        super("m:chr");
+
+        this.root.push(new MathAccentCharacterAttributes({ accent }));
+    }
+}