Add documentation on how to use Aider for further developing of Wasp AI / Mage generated apps

[Martinsos]

Continuation on https://github.com/wasp-lang/wasp/issues/1641 .

In the part of the docs about how to work on AI created app, add instructions on how to do it with Aider. We should provide some very basic instruction to what Aider is, suggest how to use it with Wasp, potentially also suggest how to enrich prompts to work better for Wasp (if that makes sense? Not sure yet what we can suggest here that is also practical for them to do manually).

We should also add short instructions in Mage, in the popup that happens once app is successfully generated -> short mention of Aider + link to the docs we wrote in this issue.

We should also add these short instructions in the final text of the output when app is generated via Wasp CLI.

• [ ] In Wasp docs, under "AI > Iterating on AI generated app" (making up these titles but something like this) -> write how to use Aider for this.
• [ ] Add short instructions to Mage, in the popup on successful generation, that mention Aider and link to the docs above.
• [ ] Add the same short instructions in the Wasp CLI upon successful AI app generation.

[Martinsos]

@jankovidakovic took an initial stab at writing a piece of Wasp docs, under "AI > Iterating on AI generated app": https://www.notion.so/wasp-lang/RFC-Mage-Aider-tutorial-by-Janko-Vidakovic-36317911d30c431fa6cdb664c8a6ba54?pvs=4 . It can't be directly pasted into our docs, but should serve as a good starting point. We should rewrite it a bit possibly, to fit better into docs, maybe drop or emphasize some parts, and that should be it.