Highlight doc comments distinctively

[peter-b]

LCB doc comment blocks are distinguished from normal comment blocks by an extra initial star, i.e. /** ... */.

It would be good to highlight doc comment blocks in a distinctive way to show that they're not just normal comments.

Suggested by @macMikey.

[macMikey]

Are we still interested in this? It's going to require a change over here and a change in the syntax themes. I have contacted Mr. Hall, as well, to see if he's interested.