Add auto tune PID

[Dtcreation]

Description

Auto tune PID

Steps to Reproduce

1.Add a menu for auto tune PID

Expected behavior: Do not use the host to do PID

Actual behavior: No possibility

Additional Information

[Chlorel]

You can use Pronterface, but connected with usb ... and set your PID with a command like : M303 E(n) S(t) C(c) with : n : extruder number ( -1 for bed ... 0 for first ... 1 for second ...) t : your optimal temperature ( i set it to 200 ) c : autotune test count ( i use 4 ... but you can set more )

example : M303 E0 S200 C4 will check your PID seting at extruder 0 for 4 time once done you get suggested Kp, Ki Kd value just set them with M301 P(Kp) I(Ki) D(Kp) and dont forget to store value to eeprom M500

[Dtcreation]

Yes, but il will be nice to have it dirrectly on the screen

[Chlorel]

i tried ... but ... not that easy to do ... every string is sended to LCD screen with a send serial command ...