v0.2.4

Actors v0.2.4

Diff since v0.2.3

• supervisors can detect and handle node failures,
• checkpointing (first draft),
• enhanced error handling documentation,
• reorganized documentation (diátaxis framework)

Closed issues:

• Basic Error Handling (#16)
• Specify Actors v0.3 - Error Handling (#18)
• Improve Registry (#23)