Added option to save reachable positions

Added an optional parameter to both 2D and 3D plotting to save_to_file. If set, the calculated reachable coordinates will be saved to a .mat file

Adopt Matlab convention for helper files

No changes to functionality. Updated helpers folder to fit Matlab convention.

Fixed documentation isssues

No changes to implementation otherwise

Finished 2D and 3D reachable workspace plots

v1.0.0

Added extra functions

v0.1.0

Created base case for plotting the reachable workspace for 2D robotic arms.