Create section properties section

src/file/document/body/section-properties/doc-grid/doc-grid.ts

@@ -0,0 +1,13 @@
+import { XmlComponent } from "file/xml-components";
+import { DocGridAttributes } from "./doc-grid-attributes";
+
+export class DocumentGrid extends XmlComponent {
+    constructor(linePitch: number) {
+        super("w:docGrid");
+        this.root.push(
+            new DocGridAttributes({
+                linePitch: linePitch,
+            }),
+        );
+    }
+}