Add MMU2S gcode (so Linux Users can access them)

[hh]

The test prints are available on the desktop after installing the .dmg or '.msi' for other operating systems. The .appImage and .tgz for linux does not include them.

I spoke with Marek via support and he sent me the zip file containing these gcodes via email.

Super helpful, but it will have to be done again and again for any other linux users. If merged, this PR will allow others to download these files. Would be great if all prusa gcodes were here.

Ideally they would be linked from https://www.prusa3d.com/printable-3d-models/.

https://www.prusa3d.com/drivers/

[hh]

• iimaginarium support ticket link debugging MMU2S w/ Marek: https://gitlab.ii.coop/ii/coop/iimaginarium/issues/7
• Files from Marek: https://www.dropbox.com/s/mcvbmpumiiup0gg/MK3SMMU2S.zip?dl=0&file_subpath=%2FMK3SMMU2S