* Remove V3 and V4 bearing tops based on REVA top
- The ball used in newer Ploopy trackballs doesn't fit in the REVA top -
it's just slightly too big.
- I've designed an updated BTU mod for the REVC top, which should work
fine with the older ball.
* Move README images to img/ subfolder
* Add blank REVC STEP and STL files
- These are the official Ploopy Top REVC, edited to remove the bearing
sockets.
- The idea is that these can be used for any future mods to use
different bearings.
* Add REVC versions of the BTU top STEP and STL files
* Rename v4 BTU mod FreeCAD file to match naming scheme
* Remove FreeCAD file for v4 BTU top
- It's not really relevant any more as it only works for the smaller
ball
* Add REVC BTU top mod to the README
- Also explains that the v3 and v4 ones can still be found in the commit
history
George Bryant