Merge pull request NativeScript#1676 from NativeScript/niliev/elevation

docs: note added about default elevation value

Author: tsonevn

docs/ui/styling.md

@@ -621,7 +621,7 @@ Example:
 {% angular %}
 ```CSS
 .tvElevation{
-    android-elevation:5;
+    android-elevation: 5;
 }
 ```
 ```XML
@@ -635,8 +635,16 @@ Example:
 [Demo](https://play.nativescript.org/?template=play-ng&id=hfogBI)
 {% endangular %}
 
+> **Note:** Since NativeScript 5.4, the buttons on Android have default elevation (shadow) of 2, due to the new elevation support. Removing the shadow will allow you to create transparent button. To explicitly remove the elevation, set the `android-elevation` property to 0 as shown below:
+```CSS
+.btn-no-elevation {
+    android-elevation: 0;
+}
+```
+
 More info about this property can be found in [Create Shadows and Clip Views](https://developer.android.com/training/material/shadows-clipping) article.
 
+
 ### Using the androidDynamicElevationOffset property <sup>Android</sup>
 
 Another property introduced with {N} 5.4 is `androidDynamicElevationOffset`. This property allows setting an elevation, which will be shown when an action was performed. Those actions can be, for example, `tap`, `touch` etc.