[Grbl_Esp32 Issue#297] Auto C-axis for plunge knife or drag knife CNCs

Please describe the feature you would like implemented
When there is an XY movement,, I think it would be cool if there was an Auto C axis calculation based on the direction – atan2(#,#).
You would put in a $ setting for how many steps for a full revolution and GRBL would rotate the knife what ever direction the head is moving.
$ long int steps per revolution
$ boolean continuous rotation enable
$ boolean autocalculate C-Axis
$ long int plunge delay in milliseconds
$ int max angle before lift

Then it would need the $115,, $125 and ignore $105 and

Why do you think this would improve Grbl_ESP32?
I see this on textile machines and fancier CNC mills with oscillating knifes. I don’t think the Arduino Uno has the processing power to fit this in.
What do you need the feature for?
Textile cutting,, laser diode output shape compensation,, Cricut Maker hacking,,
Will this feature appeal to a lot of users?
Probably not,, but It’s a cool feature and super useful.