Update README.md (#549)

Author: ManiProjs

README.md

@@ -3,6 +3,7 @@
 ## Table of Contents
 
 - [Introduction](#introduction)
+- [Important Notice](#important-notice)
 - [Examples](#examples)
 - [Installation](#installation)
 - [Features](#features)
@@ -40,6 +41,9 @@
 - Support running the application as [a daemon](#daemon)
 - Offer a wide range of [CLI commands](#cli-commands)
 
+## Important Notice
+spotify-player throws error "Login failed with reason: Bad credentials" when authenticating from 7/29/2024 because Spotify removed username & password authentication from API through Mercury/Hermes. Please use [librespot-auth repository](https://github.com/dspearson/librespot-auth). For more details, see [#520](https://github.com/aome510/spotify-player/issues/520)
+
 ## Examples
 
 A demo of `spotify_player` `v0.5.0-pre-release` on [youtube](https://www.youtube.com/watch/Jbfe9GLNWbA) or on [asciicast](https://asciinema.org/a/446913):