docs: left-align skills download heading

README.en.md

@@ -423,9 +423,9 @@ pnpm typecheck    # Type-check without emitting
  </picture>
 </a>
 
-<div align="center">
+## Skills Download History
 
-<h2>Skills Download History</h2>
+<div align="center">
 
 <a href="https://skill-history.com/narcooo/inkos">
   <img alt="Skills Download History" src="https://skill-history.com/chart/narcooo/inkos.svg" />

README.ja.md

@@ -407,9 +407,9 @@ pnpm typecheck    # 出力なしで型チェック
  </picture>
 </a>
 
-<div align="center">
+## Skills Download History
 
-<h2>Skills Download History</h2>
+<div align="center">
 
 <a href="https://skill-history.com/narcooo/inkos">
   <img alt="Skills Download History" src="https://skill-history.com/chart/narcooo/inkos.svg" />

README.md

@@ -425,9 +425,9 @@ pnpm typecheck    # 类型检查
  </picture>
 </a>
 
-<div align="center">
+## Skills Download History
 
-<h2>Skills Download History</h2>
+<div align="center">
 
 <a href="https://skill-history.com/narcooo/inkos">
   <img alt="Skills Download History" src="https://skill-history.com/chart/narcooo/inkos.svg" />