message: fix MD pill serialization
diff: @@ -69,7 +69,7 @@ class PlainWithPillsSerializer {
  case 'plain':
  return node.data.get('completion');
  case 'md':
  - return `[${ node.text }](${ node.data.get('href') })`;
  + return `[${ node.data.get('completion') }](${ node.data.get('href') })`;
  case 'id':
  return node.data.get('completionId') || node.data.get('completion');
  }
  