Will I get documentation?

Yes, two docs per extension:

• User guide (admin-facing), how a store admin installs, configures, uses the extension. Screenshots, troubleshooting tips, common pitfalls.
• Dev guide (engineer-facing), architecture, extension points, how to override, how to add custom logic on top, API reference.

Both are markdown in the repo (so version-controlled), plus a rendered HTML version. We write docs the way we wish vendors did when we’re consuming their extensions, thorough, honest, and answering the questions you’d actually ask.