Update Configuration.h

Annotate Bilby CNC thermistor (#7).
Adjust extruder steps per mm.
Merge pull request #1 from fsantini/mlaws_orig

Solidoodle 3 bed size with conditional switch
Update Configuration.h

Raise max extruder temp to 225 to suit custom hot ends with more accurate temp readings. User beware for standard hot ends!
Update README.md

Add solidoodle 2/3 instructions.
Update README.md

Re-add preconfigured Arduino 022 link.
Merge https://github.com/mlaws/solidoodle2-marlin into mlaws_orig