Adjustment to announcement text for glibc 2.37 --- Mention Reviewers and Release branches.

[Carlos O'Donell]

Sam James (Gentoo) brought to my attention during the glibc 2.36
release that some distributions did not know about the release/*
branches. We discussed adding more text to the release announcement
to highlight the purpose of the branches.

For glibc 2.37 I've added the following text to the release announcement:
~~~
Distributions are encouraged to regularly pull from the release/*
branches corresponding to the release they are using.  The release
branches will be updated with conservative bug fixes and new
features while retaining backwards compatibility.
~~~

I'm open to any suggestions for specific wordsmithing here, but the
intent is to continue to encourage distribution participation in the
stable branches as we do today... starting with using them.

The last 3 releases have seen ~700 commits backported to fix bugs
or implement ABI-neutral features (like IFUNCs).

Thank you to everyone doing the backporting work! :-)

I also called out everyone in the release announcement who had their
name in a Reviewed-by tag.

Thank you to everyone doing reviews! :-)

-- 
Cheers,
Carlos.