Be able to configure highlight text token

Logseq and Roam uses ^^.
but Obsidian, Typora, AiWriter, etc… uses ==.

It would be nice if we can configure it to better interop with other editors (I know that Markdown doesn’t have an Highlight standard).

Version 0.3.0 supports == as highlighting. Is that enough?

Yeah, and many thanks to deja for addin it