Add Moonraker Support

[sphawes]

Moonraker allows for file upload using an HTTP POST request. Documentation is here.

settings.json will need to be changed to support different printer types.

[GerritPlehn]

PR #7 implements Klipper/Moonraker.

[matmen]

For printers utilizing a separate host computer (all Klipper 3d printers), I wonder if other alternatives are better suited for the task.

Mounting an SMB share on the host computer would likely work, that way you can have one "primary" host computer (or NAS/server) all the printers would be pulling the required files off of when needed. One obvious issue here is that if the connection to the SMB share fails, all your prints will fail.

Personally, I use syncthing to replicate my ~/printer_data/gcodes directory to multiple locations, which should be faster and more reliable than plain old HTTP uploads since it's peer to peer and can sync from/to many clients at the same time. This also doesn't have the disadvantage of requiring a constant connection to the share, as all the files are saved locally. I also use the same approach to back up my config files, logs, timelapse videos and moonraker/spoolman databases.