Add Decor library

I have added [Decor](https://github.com/chemouna/decor) in the styling section

README.md

@@ -272,3 +272,4 @@ Name | License | Demo
 [DrawableView](https://github.com/PaNaVTEC/DrawableView) | [Apache License V2](https://www.apache.org/licenses/LICENSE-2.0) | <img src="/art/DrawableView.gif" width="49%">
 [Material Shadow 9-Patch](https://github.com/h6ah4i/android-materialshadowninepatch) | [Apache License V2](https://www.apache.org/licenses/LICENSE-2.0) | <img src="/art/android-materialshadowninepatch.png" width="49%">
 [SimpleFingerGestures](https://github.com/championswimmer/SimpleFingerGestures_Android_Library) | [Apache License v2](https://github.com/championswimmer/SimpleFingerGestures_Android_Library/blob/master/LICENSE) | <img src="/art/SimpleFingerGestures1.gif" width="49%"> <img src="/art/SimpleFingerGestures2.gif" width="49%"> <img src="/art/SimpleFingerGestures3.gif" width="49%"> <img src="/art/SimpleFingerGestures4.gif" width="49%">
+[Decor](github.com/chemouna/decor) | [Apache License V2](https://www.apache.org/licenses/LICENSE-2.0) | <img src="/art/Decor.png" width="100%">