Help ObiRopeCursor documentation is out of date

[protomenace]

Thanks for pointing this out! I've updated the documentation.

For convenience:
- The cursor mu is the normalized position of the cursor along the rope. This is where new particles will be inserted or removed.
- The source mu is the normalized position from which particles will be copied from, when inserting them at the cursor mu. This is useful if your rope has non-uniform thickness, color, or any other property.

Excellent, thank you!