FR: allow newlines, images etc in highlights

Describe the feature you'd like

Hi,

I noticed that currently the highlighting feature does not handle equations nor images well.

Here is an example with images:

Here is an example with multiple lines:

There is a bounty: meaning that anyone that gets this working will receive 20 US dollars (or currency equivalent). I have a track record for being fair.

Describe the benefits this would bring to existing Karakeep users

Better highlights

Can the goal of this request already be achieved via other means?

No

Have you searched for an existing open/closed issue?

• I have searched for existing issues and none cover my fundamental request

Additional context

No response