v1.0.0 for hardware-PWM on SAMD21/SAMD51 boards

### Releases v1.0.0

1. Initial coding for **SAMD21/SAMD51 boards** such as `NANO_33_IOT`, `ITSYBITSY_M4`, `SEEED_XIAO_M0`, `SparkFun SAMD51_Thing_Plus`, etc. using
- [Arduino SAMD core](https://github.com/arduino/ArduinoCore-samd)
- [Adafruit SAMD core](https://github.com/adafruit/ArduinoCore-samd)
- [Seeed-Studio SAMD core](https://github.com/Seeed-Studio/ArduinoCore-samd)
- [Sparkfun SAMD core](https://github.com/sparkfun/Arduino_Boards)
- [Industruino SAMD core](https://github.com/Industruino/IndustruinoSAMD)

Author: khoih-prog

changelog.md

@@ -11,8 +11,6 @@
 
 ## Table of Contents
 
-## Table of Contents
-
 * [Changelog](#changelog)
   * [Releases v1.0.0](#releases-v100)