Improve visibilty of the drag pane when viewed vertically (#2713)

Co-authored-by: Opender Singh <opender.singh@konghq.com>

packages/insomnia-app/app/ui/components/settings/general.tsx

@@ -193,8 +193,9 @@ class General extends PureComponent<Props, State> {
               setting="useBulkHeaderEditor"
             />
             <BooleanSetting
-              label="Vertical request/response layout"
+              label="Use vertical layout"
               setting="forceVerticalLayout"
+              help="Stack application panels (e.g. request / response) vertically instead of horizontally."
             />
           </div>
           <div>

packages/insomnia-app/app/ui/css/components/spec-editor.less

@@ -1,4 +1,3 @@
-
 #swagger-ui-wrapper {
   height: 100%;
   overflow-y: scroll;

packages/insomnia-app/app/ui/css/components/wrapper.less

@@ -161,6 +161,7 @@
     grid-column-end: span 3;
     grid-row-start: 4;
     grid-row-end: span 1;
+    border-top: 1px solid var(--hl-md);
   }
 
   .drag--pane-horizontal {