DISSTANS Version 2.2

Minor release adding some functionality:

• Added the t_min and t_max options to Network.gui() (see #9).
• Added the function to calculate interpolated velocity, strain, and rotation fields with get_field_vel_strain_rot. There is a corresponding Tutorial 6 showing the feature.
• Added the CITATION.cff file.

Full Changelog: v2.1.1...v2.2