The markdown for the publish-view is generated
using the `Note.extractMeta` method.
It uses meta-marked to separate the metadata from markdown.
Only the raw markdown is then sent to the client,
so it cannot respect the `breaks` option.
This adds an evil hack to send the `breaks` option with the markdown
if it is contained in the metadata block.
Fixes https://github.com/hedgedoc/hedgedoc/issues/2358
Signed-off-by: David Mehren <git@herrmehren.de>