[ghc-steering-committee] Section numbering

Joachim I think it'd be super-helpful to number the sections of a GHC proposal. So much easier to navigate; and to refer to points in the discussion. It's easy: just add .. sectnum:: to the preamble. Could you do that to the template? But one other thing. If you look at https://github.com/Gertjan423/ghc-proposals/blob/quantified-constraints/prop... where I did that, you'll see that everything is under Section 1. better to give guidance about how to make a top-level heading that is just a heading, so only the other items have numbers. Otherwise every section numbers starts "1." which is silly. Thanks Simon