Add poet epigraphs to blog posts and refine formatting

content/blog/python-async-guide.md

@@ -2,6 +2,9 @@
 title: "Python Async: Beyond the Basics"
 date: 2026-05-12T11:00:00+08:00
 draft: false
+poet: |
+  They also serve who only stand and wait.
+  ——John Milton，英国，1608–1674
 description: "Understanding the event loop, writing proper async context managers, and avoiding the most common pitfalls with asyncio.gather and cancel scopes."
 tags:
   - Python