Syntax highlight for DocC blocks

[tib]

Currently when I edit DocC or other Markdown files with custom block support, there is no syntax highlight for the block directives.

It would be nice to have proper syntax highlight for custom blocks, e.g.:

@Tutorial {
    ## My tutorial

    lorem ipsum dolor sit amet
}

In this case I'd expect the Tutorial word to have a different color, also everything inside the brackets should have proper highlights.

Many thanks for considering this. 🙏