Improve planning for complex tasks

[ErikBjare]

After the Cognition Labs announcement of Devin yesterday (https://twitter.com/cognition_labs/status/1767548763134964000), which was very reminiscent of gptme, I noticed that they have this "Planner" module which has a Current focus: ... and a list of steps/checkboxes in markdown.

Would be interesting in working to improve planning in gptme, potentially with the help of https://github.com/ErikBjare/gptme/issues/61.