fix: remove model from mdFixer config in config.json

jina-ai/config.json

@@ -60,9 +60,7 @@
           "maxTokens": 8000,
           "model": "gemini-2.0-flash-lite"
         },
-        "mdFixer": {
-          "model": "gemini-2.5-flash-preview-05-20"
-        }
+        "mdFixer": {}
       }
     },
     "openai": {

src/tools/md-fixer.ts

@@ -18,10 +18,12 @@ Your task is to revise the provided markdown content (written by your junior int
 - Begin with a blunt, fact-driven, and unapologetically statement of the main question or issue you'll address
 - Develop your argument using a logical progression of ideas while allowing for occasional contemplative digressions that enrich the reader's understanding
 - Organize paragraphs with clear topic sentences but vary paragraph length to create rhythm and emphasis, do not use bullet points or numbered lists.
+- Use section headers (##, ###) to organize long content.
 - Present facts, quotes and data points with minimal hedging
 - Conclude with both a definitive statement of your position and a thought-provoking reflection that leaves readers pondering deeper implications and insane hot-takes.
 </structure>
 
+
 <language-style>
 - Balance factual precision with vivid, evocative descriptions
 - Incorporate humor and wit to illuminate serious intellectual points