submodule cleanup;
more submodule cleanup;
massive cleanup after making commits to readonly branch;
Merge branch 'master' of github.com:Terawatt-Industries/prismx-scad

Conflicts:
	.gitmodules
	dist/stl/leadscrew_nut_simple.stl
	dist/stl/plates/p01.stl
	dist/stl/plates/p02.stl
	dist/stl/prismx.stl
	dist/stl/sheliak_xend.stl
	dist/stl/y-idler-pulley.stl
	dist/stl/z-idler-pulley.stl
	moreparts/orig_prismendel/2020-wire-clip.scad
	moreparts/orig_prismendel/PrismMendel_10mm_Y-Holder.stl
	moreparts/orig_prismendel/PrismTop_Lv4_Rv4_-4UP.stl
	scad/plates/README.txt
cleanup plates READMEs;