Update WebTwain_Viewer.md

Removed an extra e from custom

Author: ogg25

info/api/WebTwain_Viewer.md

@@ -222,15 +222,15 @@ createCustomElement(
 
 interface CustomElement {
     /**
-     * Show the custome element.
+     * Show the custom element.
      */
     show(): boolean;
     /**
-     * Hide the custome element.
+     * Hide the custom element.
      */
     hide(): boolean;
     /**
-     * Remove the custome element.
+     * Remove the custom element.
      */
     dispose(): boolean;
 };