procession-espnow v0.2.0

Updated the Talker interface to the subscribe/publish terms

• This intends to make the language equivalent between Procession and the code in a Talker.
• sendMessage() is now publish().
• getLastReceivedMessage() is still available but subscribe("topic") is preferred.

procession-espnow v0.1.0

First release.

• Enables creating a "Mediator," an Arduino ESP32 that connects to Procession via serial (typically direct USB connection).
• Enables creating "Talkers" (also Arduino ESP32s) that communicate bidirectionally to the Mediator via ESP-NOW.
• Users can "publish" and "subscribe" to data topics shared by Procession and the Talkers.
• Requires the Arduino core "esp32 by Espressif Systems" (min v3.3.0)