chore(test): add test for markdown import

src/services/import/markdown.spec.ts

@@ -0,0 +1,19 @@
+import { trimIndentation } from "../../../spec/support/utils.js";
+import markdownService from "./markdown.js";
+
+describe("markdown", () => {
+    it("converts h1 heading", () => {
+        const result = markdownService.renderToHtml(trimIndentation`\
+            # Hello
+            ## world
+            # another one
+            Hello, world
+        `, "title");
+        expect(result).toBe(trimIndentation`\
+            <h2>Hello</h2>
+            <h2>world</h2>
+            <h2>another one</h2>
+            <p>Hello, world</p>
+        `);
+    });
+});