CONTRIBUTING.md suggestion

[Jesper Skov]

Hi again,

I have an additional suggestion for CONTRIBUTING.md changes.


In the Code Review section:

 If any changes are needed, you would push additional commits to the
 branch from which you made the pull request.

Maybe add something to the effect that;

 These additional commits should have commit message describing the
 change, not the bug issue name. Note that this will upset jcheck.


(maybe jcheck should be fixed to only complain if the original
commit has a bad message, so the last sentence is not needed)


Cheers,
Jesper