v2.1.1

This release improves the introductory and visualization tutorial. Ensures both are Google Colab compatible with working badges.

Changes:

• Update intro_tutorial to warn users to ensure up to date version, and make colab compatible #1739, #1744
• Improve new/experimental Solara based visualization to ensure pause button works #1745
• Fix bug in space.py -> get_heading() #1739