When creating a webhook integration or creating a new one, it is a pain to
create or update the screenshots in the documentation. This commit adds a
tool that can trigger a sample notification for the webhook using a fixture,
that is likely already written for the tests.
Currently, the developer needs to take a screenshot manually, but this could
be automated using puppeteer or something like that.
Also, the tool does not support webhooks with basic auth, and only supports
webhooks that use json fixtures. These can be fixed in subsequent commits.
Puneeth Chaganti