docs: refresh English and Japanese README for globalization

Assisted-by: Claude (AWS Bedrock anthropic.claude-3-haiku-20240307-v1:0)
Assisted-by: GitHub Copilot (GPT-5.3-Codex)

Author: amilkh

README.ja.md

@@ -1,5 +1,5 @@
 # egmapjs
-leafletjs x 地理院地図(GSIMAP)  
+leafletjs x 地理院地図(GSIMAP)
 
 ## サンプル
 京都いしぶみマップ