Use `commands` instead of `command` (plural versus singular)

[deadcoder0904]

OpenCode has lots of issues with singular and plural. They used to use singular but they have gone to plural because it makes sense grammatically.

OpenCode also changed its docs: https://opencode.ai/docs/commands/

I noticed when I did this:

$ ocx add kdco/workspace

It added to command instead of commands which I already had:

$ ls .opencode/command*

.opencode/command:
review.md

.opencode/commands:
commit.md

[kdcokenny]

Yep, this will be handled in the next version. Will be making OCX much more flexible to avoid issues like this in the future.