chore: set html lang to ja

tomohxx · tomohxx · commit f27f05a976f0 · 2026-07-02T20:41:08.000+09:00
diff --git a/index.html b/index.html
@@ -1,5 +1,5 @@
 <!doctype html>
-<html lang="en">
+<html lang="ja">
   <head>
     <meta charset="UTF-8" />
     <!-- <link rel="icon" type="image/svg+xml" href="/favicon.svg" /> -->
