Discussion - Completion API - Allow users to create their own completion specs #131

Is your feature request related to a problem? Please describe.
We currently support a discrete set of completions https://docs.warp.dev/features/tab-completions, and users may have other tools that are either proprietary or aren't supported by us.

Describe the solution you'd like

1. Open-source the completion specs, and allow the community to contribute new ones in a public repo.
2. Allow linking new completions built privately on the fly.

Additional context
Requested by pugologist in Discord