More style tweaks to panel option group add button

packages/grafana-ui/src/components/PanelOptionsGroup/_PanelOptionsGroup.scss

@@ -54,6 +54,8 @@
 
 .panel-options-group__title {
   font-size: 1.1rem;
+  position: relative;
+  top: 1px;
 }
 
 .panel-options-group__body {

packages/grafana-ui/src/components/ThresholdsEditor/_ThresholdsEditor.scss

@@ -1,5 +1,5 @@
 .thresholds {
-  margin-bottom: 10px;
+  margin-bottom: 20px;
 }
 
 .thresholds-row {