Readme: use an optimized art

Credits goes to @mathieu-aubin :) Closes #183

Signed-off-by: enricocid <enrico2588@gmail.com>

CONTRIBUTORS.md

@@ -12,6 +12,8 @@ If you think you should be listed, don't hesitate to notify me! :)
 
 - [**Steven Schoen**](https://github.com/DSteve595) for the search function [fixes](https://github.com/enricocid/Music-Player-GO/commit/1c27ff3421dbf7820608237dc60a974955efb022) and quick [support](https://github.com/reddit/IndicatorFastScroll/issues/30)
 
+- [**Mathieu Aubin**](https://github.com/mathieu-aubin) for the readme's [GIF optimization](https://github.com/mathieu-aubin/tempgif)
+
 
 ### General credits:
 

LIBRARIES.md

@@ -14,6 +14,8 @@
 
 
 ### Repo and project UI, screenshots, etc.
+- [GIF optimization script](https://github.com/mathieu-aubin/tempgif) by [**Mathieu Aubin**](https://github.com/mathieu-aubin)
+
 - [**Source sans pro**](https://fonts.google.com/specimen/Source+Sans+Pro) font by Google Fonts
 
 - [**Screener - Better screenshots**](https://play.google.com/store/apps/details?id=de.toastcode.screener) app by [**Toastcode**](https://toastco.de/)

README.md

@@ -6,15 +6,15 @@
 [![Privacy policy](https://img.shields.io/static/v1?label=Privacy-policy&message=read&color=ef9a9a)](https://github.com/enricocid/Music-Player-GO/blob/master/PRIVACY.md)
 [![FAQ](https://img.shields.io/static/v1?label=FAQ&message=read&color=ce93d8)](https://github.com/enricocid/Music-Player-GO/blob/master/FAQ.md)
 [![3rd party libs and tools](https://img.shields.io/static/v1?label=Libs/tools&message=13&color=9fa8da)](https://github.com/enricocid/Music-Player-GO/blob/master/LIBRARIES.md)
-[![Contributors](https://img.shields.io/static/v1?label=Contributors&message=37&color=81d4fa)](https://github.com/enricocid/Music-Player-GO/blob/master/CONTRIBUTORS.md)
+[![Contributors](https://img.shields.io/static/v1?label=Contributors&message=38&color=81d4fa)](https://github.com/enricocid/Music-Player-GO/blob/master/CONTRIBUTORS.md)
 [![Supported formats](https://img.shields.io/static/v1?label=Formats&message=read&color=80cbc4)](https://github.com/enricocid/Music-Player-GO/blob/master/FORMATS.md)
 
 [![API](https://img.shields.io/static/v1?label=API&message=21&color=a5d6a7)](https://developer.android.com/about/versions/android-5.0.html)
 [![TAG](https://img.shields.io/static/v1?label=Tag&message=v4.2.6&color=ffe082)](https://github.com/enricocid/Music-Player-GO/releases/tag/v4.2.6)
 
 ![TAG](https://img.shields.io/static/v1?label=Languages&message=14)
 
-<img align="right" src="https://raw.githubusercontent.com/enricocid/Music-Player-GO/master/mpgo-4-2-4.gif" height="500px"/>
+<img align="right" src="https://raw.githubusercontent.com/enricocid/Music-Player-GO/master/mpgo-4-2-4_quality55.webp" height="500px"/>
 
 
 # Features: