Summary

Adds migration guide documentation for the deprecation of passing portrayal arguments directly to draw_agents() and draw_propertylayer() methods, introduced in PR #3144.

Migration guide entry

The new section shows users how to update their code:

# Old
renderer.draw_agents(agent_portrayal=agent_portrayal)
renderer.draw_propertylayer(propertylayer_portrayal)

# New
renderer.setup_agents(agent_portrayal).draw_agents()
renderer.setup_propertylayer(propertylayer_portrayal).draw_propertylayer()

Fixes a violation in the deprecation policy, should have happened in #3144 at the latest when the PendingDeprecationWarning was updated to FutureWarning.