added Spacing for paragraphs and ParagraphStyle

ts/tests/docx/paragraph/spacingTest.ts

@@ -0,0 +1,24 @@
+import { expect } from "chai";
+
+import { Spacing } from "../../../docx/paragraph/spacing";
+import { Formatter } from "../../../export/formatter";
+
+describe("Spacing", () => {
+    describe("#constructor", () => {
+        it("should set the properties given", () => {
+            const spacing = new Spacing({before: 100, after: 120, line: 150});
+            const tree = new Formatter().format(spacing);
+            expect(tree).to.deep.equal({
+                "w:spacing": [{_attr: {"w:after": 120, "w:before": 100, "w:line": 150}}],
+            });
+        });
+
+        it("should only set the given properties", () => {
+            const spacing = new Spacing({before: 100});
+            const tree = new Formatter().format(spacing);
+            expect(tree).to.deep.equal({
+                "w:spacing": [{_attr: {"w:before": 100}}],
+            });
+        });
+    });
+});