File-specific rules

What feature would you like to see?

I'd like to setup rules that are automatically injected into chat context based on the file suffixes being worked with. I have very little confidence in the finer details of my conventions being considered if the agent has to find them within the larger AGENTS.md file.

Rules that are automatically injected would enable smaller AGENTS.md files, thus ensuring the Agent is only aware of the details that are actually pertinent to the current conversation/work.

Additional information

Claude and Cursor have similar features.