Updates text of generate-webhook-url-basic.md to replace the use of
the "Create the channel" step.
Removes {!create-channel.md!} from all the integrations docs that
also include {!generate-webhook-url-basic.md!}.
Fixes#32269.
Creates an incoming webhook integration for Patreon. The main
use case is getting notifications when new patrons sign up.
Fixes#18321.
Co-authored-by: Hari Prashant Bhimaraju <haripb01@gmail.com>
Co-authored-by: Sudipto Mondal <sudipto.mondal1997@gmail.com>