Update README.md

Author: marcmerlin

README.md

@@ -68,6 +68,12 @@ Please do refer to --led-multiplexing=<0..17> mentioned below and try all values
 These should be labelled as "special" in the table above. They are not supported by this
 lib, as it only supports non PWM panels (until someone contributes PWM support).
 
+PWM/E-PWM/S-PWM Panels
+----------------------
+Newer PWM panels are not currently supported by this lib, but support would really be appreciated.
+- https://github.com/hzeller/rpi-rgb-led-matrix/pull/1353 is one early attempt that needs testing/updating
+- https://github.com/hzeller/rpi-rgb-led-matrix/issues/466 is a list of spec sheets
+- https://github.com/hzeller/rpi-rgb-led-matrix/issues/1825 is the master bug tracking PWM efforts
 
 Raspberry Pi up to 4 supported
 ------------------------------