Create issue template for creating crews

[whoabuddy]

Would be great to standardize this so others can fill it in, early thoughts on structure:

• high-level purpose/goal of the crew
• definitions for agents
• definition for tasks
• definition of execution loop

There's a great CrewAI GPT too that can help with thinking through these structures as well as developing the code: https://chat.openai.com/g/g-qqTuUWsBY-crewai-assistant