Updated the Git-related integrations that support branch filtering:
- Removed the branch-filtering configuration option, and its macro.
- Added a new macro that integrates the branch-filtering instruction
with the Generate-URL step.
The new macro `generate-webhook-url-with-branch-filtering` builds off of
the `generate-webhook-url-basic` macro, adding only the branch filtering
instruction. But, it does not re-use the macro, instead duplicates it,
to avoid the newline break that would be added otherwise.
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.
markdown-include is GPL licensed.
Also, rewrite it as a block processor, so that it works correctly
inside indented blocks.
Signed-off-by: Anders Kaseorg <anders@zulip.com>
