fix: Fix markdown outputs not rendering

Signed-off-by: Tomas Kislan <tomas@kislan.sk>

Author: tkislan

src/notebooks/deepnote/deepnoteDataConverter.ts

@@ -236,6 +236,8 @@ export class DeepnoteDataConverter {
             for (const item of output.items) {
                 if (item.mime === 'text/plain') {
                     data['text/plain'] = new TextDecoder().decode(item.data);
+                } else if (item.mime === 'text/markdown') {
+                    data['text/markdown'] = new TextDecoder().decode(item.data);
                 } else if (item.mime === 'text/html') {
                     data['text/html'] = new TextDecoder().decode(item.data);
                 } else if (item.mime === 'application/json') {
@@ -392,6 +394,10 @@ export class DeepnoteDataConverter {
                             );
                         }
 
+                        if (data['text/markdown']) {
+                            items.push(NotebookCellOutputItem.text(data['text/markdown'] as string, 'text/markdown'));
+                        }
+
                         if (data['text/plain']) {
                             let mimeType = 'text/plain';
                             // deepnote-toolkit returns the text/plain mime type for big number outputs