Update favicon images

Author: yasulab

_includes/head.html

@@ -60,9 +60,9 @@
   {% endif %}
 
   <!-- Favicon -------------------------- -->
-  <link rel="icon" href="/img/coderdojo.svg"  sizes="any" type="image/svg+xml">
-  <link rel="icon" href="/img/coderdojo.webp" sizes="512" type="image/webp">
-  <link rel="apple-touch-icon" href="/img/apple-touch-icon.png"> <!-- 192x192px -->
+  <link rel="icon" href="/img/cpj.svg"  sizes="any" type="image/svg+xml">
+  <link rel="icon" href="/img/cpj.webp" sizes="512" type="image/webp">
+  <link rel="apple-touch-icon" href="/img/cpj.png"> <!-- 192x192px -->
   <!-- MEMO: デフォルト用に favicon.ico をルートディレクトリにも置く: /favicon.ico -->
 
   <!-- CSS Framework -------------------------- -->