Fix installation command for firebase/php-jwt

Author: ojhaujjwal

html/index.html

@@ -375,7 +375,7 @@ <h3 class="panel-title">PHP</h3>
 
             <div class="panel-footer">
               <div>
-                <code>php composer require firebase/php-jwt</code>
+                <code>composer require firebase/php-jwt</code>
               </div>
 
             </div>