Remove keyboard shortcut panel

Support for keyboard shortcuts will be re-evaluated and re-worked in the next release if deemed to be a necessary feature as feedback has shown low usage.

web/templates/admin/panel.html

@@ -2,9 +2,6 @@
 <a href="#" class="to-top">
 	<i class="fas fa-arrow-up"></i>
 </a>
-<a href="#" class="to-shortcuts">
-	<i class="fas fa-keyboard"></i>
-</a>
 
 <div class="l-header">
 	<div class="l-center">

web/templates/user/panel.html

@@ -2,9 +2,6 @@
 <a href="#" class="to-top">
 	<i class="fas fa-arrow-up"></i>
 </a>
-<a href="#" class="to-shortcuts">
-	<i class="fas fa-keyboard"></i>
-</a>
 
 <div class="l-header">
 	<div class="l-center">