style: chat message render markdown by default

src/locales/en-US/playground.ts

@@ -140,6 +140,7 @@ export default {
   'playground.image.edit': 'Edit',
   'playground.image.fitview': 'Fit View',
   'playground.chat.aithought': 'CoT',
+  'playground.chat.thinking': 'Thinking...',
   'playground.image.mask.uploaded': 'Mask Uploaded',
   'playground.image.mask.upload':
     'Upload Mask: No additional drawing allowed after upload.',

src/locales/ru-RU/playground.ts

@@ -137,6 +137,7 @@ export default {
   'playground.image.edit': 'Редактировать',
   'playground.image.fitview': 'Подогнать размер',
   'playground.chat.aithought': 'Рассуждение (CoT)',
+  'playground.chat.thinking': 'TODO: Translate key "playground.chat.thinking"',
   'playground.image.mask.uploaded': 'Маска загружена',
   'playground.image.mask.upload':
     'TODO: Translate key "playground.image.mask.upload"',

src/locales/zh-CN/playground.ts

@@ -135,6 +135,7 @@ export default {
   'playground.image.edit': '编辑图片',
   'playground.image.fitview': '适应视图',
   'playground.chat.aithought': '思考过程',
+  'playground.chat.thinking': '思考中...',
   'playground.image.mask.uploaded': '遮罩已上传',
   'playground.image.mask.upload': '上传遮罩：上传后将不可再绘制',
   'playground.params.frequency_penalty.tips': `数值介于 -2.0 和 2.0 之间。正值会根据新词在文本中已出现的频率对其进行惩罚，从而降低模型逐字重复相同内容的可能性。`,