Document /thinking

[jcubic]

The docs list all available commands:

https://opencode.ai/docs/tui/

But there are no docs for /thinking. I don't even know what that command is doing. It looks like it does nothing. I use Gemini 2.5 Pro (that's supposed to be a reasoning model), but I don't see any thinking.

It would be nice to have some docs that explain what the command is doing and how to use it.