feat: adjust default font

planning_ai/document.py

@@ -273,6 +273,7 @@ The following section provides a detailed breakdown of notable details from resp
         "execute:\n"
         "  freeze: auto\n"
         "  echo: false\n"
+        "fontfamily: libertinus\n"
         "monofont: 'JetBrains Mono'\n"
         "monofontoptions:\n"
         "  - Scale=0.55\n"
@@ -328,6 +329,7 @@ def build_summaries_document(out):
         "execute:\n"
         "  freeze: auto\n"
         "  echo: false\n"
+        "fontfamily: libertinus\n"
         "monofont: 'JetBrains Mono'\n"
         "monofontoptions:\n"
         "  - Scale=0.55\n"