chore(readme): add macOS arm64 to platform support (#104)

Added macOS arm64 to the list of supported platforms in README.md. Support was added in #97 and released in v0.6.0.

Author: n1ckoates

README.md

@@ -22,4 +22,5 @@ const decoded = encoder.decode(encoded);
 - Linux arm (RPi 1 & 2)
 - Linux arm64 (RPi 3)
 - macOS x64
+- macOS arm64
 - Windows x64