Contribution checklist v2

[Siddhesh Poyarekar]

On 08/10/19 5:31 pm, Florian Weimer wrote:
> I think we need to fix some whitespace issues first:
> 
>   <https://sourceware.org/ml/libc-alpha/2019-10/msg00132.html>
> 
> At least my local commit hook rejected the move without that change.

Those are obvious, please feel free to push them directly.

However it looks like with Joseph's comment, we're back to maintaining
ChangeLog until the end of the release since that's the point of a clean
break.  I don't have a strong opinion about it.

Siddhesh