Support text highlighting

[lcswillems]

Hello,

In markdown we can highlight text by doing ==my text==. The background would then change color. However, VSCode doesn't support this.

Possible to add support in this extension?

[baincd]

I admittedly was not familiar with this highlight syntax. But it seems it has pretty limited support among markdown processors, and because of that I'm not strongly inclined to add support for it in this extension. But I will keep it in mind.

[lcswillems]

Obsidian supports it for example. That's the only thing that keeps me using Obsidian over VSCode.