Add Discord badge to README (#1150)

Author: stephanebruckert

CHANGELOG.md

@@ -17,6 +17,7 @@ Add your changes below.
 - Added rate/request limit to FAQ
 - Added custom `urllib3.Retry` class for printing a warning when a rate/request limit is reached.
 - Added `personalized_playlist.py`, `track_recommendations.py`, and `audio_features_analysis.py` to `/examples`.
+- Discord badge in README
 
 ### Fixed
 - Audiobook integration tests

README.md

@@ -2,7 +2,7 @@
 
 ##### Spotipy is a lightweight Python library for the [Spotify Web API](https://developer.spotify.com/documentation/web-api). With Spotipy you get full access to all of the music data provided by the Spotify platform.
 
-![Tests](https://github.com/plamere/spotipy/workflows/Tests/badge.svg?branch=master) [![Documentation Status](https://readthedocs.org/projects/spotipy/badge/?version=master)](https://spotipy.readthedocs.io/en/latest/?badge=master)
+![Tests](https://github.com/plamere/spotipy/workflows/Tests/badge.svg?branch=master) [![Documentation Status](https://readthedocs.org/projects/spotipy/badge/?version=master)](https://spotipy.readthedocs.io/en/latest/?badge=master) [![Discord server](https://img.shields.io/discord/1244611850700849183?style=flat&logo=discord&logoColor=7289DA&color=7289DA)](https://discord.gg/HP6xcPsTPJ)
 
 ## Table of Contents