git-hooks: integrate ChangeLog format check

[Martin Liška]

On 5/13/20 7:53 PM, Joseph Myers wrote:
>   See the issues
> I filed athttps://github.com/AdaCore/git-hooks/issues  for the existing
> custom GCC changes and the pull request
> https://github.com/AdaCore/git-hooks/pull/12  to bring in implementations
> of many of those features (not sure if it covers everything or not).

Hey Joseph.

If I see correctly, the pull request was merged.
Are we now in a position where we can separate the GCC-specific
ChangeLog check in gcc-hooks? If so, can you please guide me
a bit?

Thanks,
Martin