Improve navBarBlur and navBarTranslucent documentation (#4681)

docs/docs/options-migration.md

@@ -419,6 +419,7 @@ Translucent TopBar, Setting `drawBehind: true` is required for this property to
 
 ```js
 topBar: {
+  drawBehind: true,
   background: {
     translucent: true
   }
@@ -435,12 +436,14 @@ topBar: {
 ```
 
 ## navBarBlur
-Blue the area behind the TopBar, Setting `drawBehind: true` is required for this property to work as expected.
+Blur the area behind the TopBar, Setting `drawBehind: true` and  topBar background `transparent: true` is required for this property to work as expected.
 
 ```js
 topBar: {
+  drawBehind: true,
   background: {
-    blur: true
+    blur: true,
+    transparent: true
   }
 }  
 ```