amandoti/cindermail

public

Embed screenshots in the Discord adapter doc, refresh Slack's

discord-adapter.md now matches slack-adapter.md's treatment: inline
screenshots at each step instead of text-only instructions. Credentials
checked before adding -- Application ID and Public Key are meant to be
public (Discord's own name for the latter says as much, it only ever
verifies a signature, never creates one), the actual Bot Token is
blurred.

Also swaps in redone Slack screenshots (install, OAuth token, signing
secret, and both delivery screenshots) with tighter redaction than the
first pass -- workspace name and creator are blurred now too, not just
the secrets themselves.