Build an alternative Slack app installation flow for self-managed instances
- On gitlab.com we can install the app directly from the marketplace.
- On self-managed we have to create the app first in the user's workspace from the manifest (automated via API), and then the user can install it (manual confirmation, probably).
- Both of these could be triggered by the current "Add to Slack" button on the "Slack application" integration settings page, so we might not need any new designs for this yet.
- Before we can access the Slack API we also need to authorize with Slack somehow, I'm not sure yet what this will look like (this could be its own investigation issue).
Edited by Markus Koller