Investigate informing users to update`general-wasp-knowledge.md` when plugin updates

[vincanger]

The current plugin logic has an init command that adds wasp knowldge to their CLAUDE.md file. But what if we update this doc and the user has already imported it. How can we get the user to update this doc?

Currently, init does the following:

• copies general-wasp-knowledge.md to their project dir
• imports it into their CLAUDE.md

So when we make changes to it, we need to introduce something like an update command.