chore: replace deprecated meta element

Author: kungfux

_includes/head.html

@@ -2,7 +2,7 @@
   <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
   <meta name="theme-color" media="(prefers-color-scheme: light)" content="#f7f7f7">
   <meta name="theme-color" media="(prefers-color-scheme: dark)" content="#1b1b1e">
-  <meta name="apple-mobile-web-app-capable" content="yes">
+  <meta name="mobile-web-app-capable" content="yes">
   <meta name="apple-mobile-web-app-status-bar-style" content="black-translucent">
   <meta
     name="viewport"