This change enable defining the notification body as HTML or Markdown. This can be very
useful to have more user-friendly notifications such as:
* applying a heading style to the `{watch_title}` to make it stand out
* creating clickable links using the `{watch_url}`, `{preview_url}` and `{diff_url}`.
Changes
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* Add a `notification_format` to the notification settings, defaults to plain text.
* Use the `body_format` parameter of Apprise's `notify` method.
Co-authored-by: Malo Jaffré <malo.jaffre@dunnhumby.com>
dgtlmoon