added notification for horizontal scrolling

Author: subhas-pramanik-09

js/activity.js

@@ -1514,6 +1514,7 @@ class Activity {
                     else if (ele.label === "Disable horizontal scrolling")
                         ele.display = true;
                 })
+                activity.textMsg(_("Horizontal scrolling enabled."),3000);
             } else {
                 enableHorizScrollIcon.style.display = "block";
                 disableHorizScrollIcon.style.display = "none";
@@ -1524,6 +1525,7 @@ class Activity {
                     else if (ele.label === "Disable horizontal scrolling")
                         ele.display = false;
                 })
+                activity.textMsg(_("Horizontal scrolling disabled."),3000);
             }
         };