Boostrap less code must be documented

We know from other places (that is PHPdoc and JSdoc comments on our functions and methods) that if you want people to consistently re-use standard code, then it is good if the chunks you expect people to reuse can be documented, and that documentation works best when it is in the code right next to the thing being documented.

Unfortunately, it seems that the LESS community does not yet have a standard convention for documenting individual chunks of code that you expect people to reuse in a standard way.

I think we should define our own convention for documenting these things, hence I am creating this coding style issue.