feat(import/markdown): maintain consistency with CKEditor for images

src/services/import/markdown.ts

@@ -34,6 +34,11 @@ class CustomMarkdownRenderer extends Renderer {
         return super.listitem(item).trimEnd();
     }
 
+    image(token: Tokens.Image): string {
+        return super.image(token)
+            .replace(` alt=""`, "");
+    }
+
     blockquote({ tokens }: Tokens.Blockquote): string {
         const body = renderer.parser.parse(tokens);
 
@@ -72,6 +77,9 @@ function renderToHtml(content: string, title: string) {
     html = importUtils.handleH1(html, title);
     html = htmlSanitizer.sanitize(html);
 
+    // Remove slash for self-closing tags to match CKEditor's approach.
+    html = html.replace(/<(\w+)([^>]*)\s+\/>/g, "<$1$2>");
+
     return html;
 }