I know how to make comments; I'm referring to the tooltip-ish part that pops up.
Like this.
Edit:
In terms on progress; I'm not working on the engine itself at the minute, following Paul's recommendation to do the tools first.
Currently I'm setting up how the LVLX format should look (for now), it's almost done; but I had a lot of stuff to do yesterday and didn't get time to finish.