feat(popover): Add Non-US help tooltip (#578)

packages/uhk-web/src/app/components/popover/tab/keypress/keypress-tab.component.html

@@ -7,6 +7,10 @@
             [width]="200"
             [options]="options"
     ></select2>
+    <icon name="question-circle"
+          data-toggle="tooltip"
+          title="Looking for a non-US character, but can't find it? Please note that USB keyboards send scancodes, not characters to your computer. Your operating system translates the scancodes to characters according to your actual OS keyboard layout. This means that you have to select the US-equivalent character of the desired key in Agent."
+          data-placement="bottom"></icon>
     <capture-keystroke-button (capture)="onKeysCapture($event)" tabindex="0"></capture-keystroke-button>
 </div>
 <div class="modifier-options">

packages/uhk-web/src/app/components/popover/tab/keypress/keypress-tab.component.scss

@@ -10,6 +10,10 @@
             position: relative;
             top: 2px;
         }
+
+        icon {
+            display: inline-block;
+        };
     }
 
     .modifier-options {