Merge pull request #527 from redfast00/master

Add warning about single-core compatibility

README.md

 # ESP32-audioI2S
+
+:warning: **This library only works on multi-core ESP32 chips like the ESP32-S3. It does not work on the ESP32-S2 or the ESP32-C3** :warning:
+
 Plays mp3, m4a and wav files from SD card via I2S with external hardware.
 HELIX-mp3 and -aac decoder is included. There is also an OPUS decoder for Fullband, n VORBIS decoder and a FLAC decoder.
 Works with MAX98357A (3 Watt amplifier with DAC), connected three lines (DOUT, BLCK, LRC) to I2S.