v2.1.0 for ESP32 & LwIP Ethernet

### Releases v2.1.0

1. Initial coding to port [AsyncUDP](https://github.com/espressif/arduino-esp32/tree/master/libraries/AsyncUDP) to ESP32 boards using `LwIP W5500, W6100 or ENC28J60 Ethernet`
2. Bump up to v2.1.0 to sync with [AsyncUDP_ESP32_SC_Ethernet v2.1.0](https://github.com/khoih-prog/AsyncUDP_ESP32_SC_Ethernet)

Author: khoih-prog

README.md

@@ -82,12 +82,12 @@ to apply the better and faster **asynchronous** feature of the **powerful** [Asy
 - When you send the response, you are **immediately ready** to handle other connections while the server is taking care of sending the response in the background
 - **Speed is OMG**
 - After connecting to a UDP server as an Async Client, you are **immediately ready** to handle other connections while the Client is taking care of receiving the UDP responding packets in the background.
-- You are not required to check in a tight loop() the arrival of the UDP responding packets to process them.
+- You are not required to check in a tight `loop()` for the arrival of the UDP responding packets to process them.
 
 
 #### Currently supported Boards
 
-1. **ESP32-based boards using `LwIP` W5500, W6100 or ENC28J60 Ethernet
+1. **ESP32-based boards using `LwIP` W5500, W6100 or ENC28J60 Ethernet**
 
 
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