The following PR fixes and improves formatting in the "What's New in Python 3.7" document, adds links to issues and authors names.

This is just one step. Somebody need to review NEWS entries and adds corresponding What's New entries if they are worth this, and later edit the wording of the final document.

New changeset 51302a5fcc557e6afc0bf1e3b371f5f37c76dc77 by Serhiy Storchaka in branch 'master':
bpo-32996: Improve What's New in 3.7. (#5983)
https://github.com/python/cpython/commit/51302a5fcc557e6afc0bf1e3b371f5f37c76dc77

New changeset 720a4b69c6b66ae5d6f447d5814bd204170c94b3 by Miss Islington (bot) in branch '3.7':
bpo-32996: Improve What's New in 3.7. (GH-5983)
https://github.com/python/cpython/commit/720a4b69c6b66ae5d6f447d5814bd204170c94b3

The most breaking change in 3.7 (according to the statistics of GitHub issues) is making async a keyword. But this change is even not mentioned in What's New.

Two things I'm familiar with that should probably be mentioned in the Library updates:

* bpo-32102: New argument capture_output for subprocess.run
* bpo-21417: Added support for setting the compression level for zipfile.ZipFile.

Thanks for the comments here.  As noted by Yury in PR 5983:  "Looks good. Keep in mind that @elprans and I will edit what's new (as we did for 3.5 & 3.6) closer to 3.7 release."

Different projects solve the problem with async in different ways. Many of them rename "async" parameter to "async_". Some renames it to "_async" or replace with an opposite parameter "sync". Some projects keep supporting of "async" in older Python versions by using var-keyword parameters, but not all are aware of this possibility. If the preferable way be described in the What's New, it would help porting to 3.7.

Another important language change missed in the What's New is keeping insertion order in dicts.

Sorry, I appreciate your work, Elvis, but the current version of PR 6978 seems containing too much insignificant details, which are not worth an entry in What's New. They distract attention from important changes. I think this PR should be significantly shortened.

To me, What's New is not a structured copy of Misc/NEWS. It serves two purposes:

1. Advertising new features.

2. Warning about possible breaks or future breaks.

If the change doesn't add a new way of doing something and doesn't break significant part of code, it is not worth mentioning in What's New.

PR 6978 also adds entries for bug fixes, which shouldn't be in this document.

Thanks for the feedback Serhiy!  I'll make an editorial pass to address the comments shortly.  In general, I prefer thoroughness in the initial What's New edit to make sure we don't miss something important.

New changeset 63536bd286097e770909052052a21804a5e09b66 by Yury Selivanov (Elvis Pranskevichus) in branch 'master':
bpo-32996: The bulk of What's New in Python 3.7 (GH-6978)
https://github.com/python/cpython/commit/63536bd286097e770909052052a21804a5e09b66

New changeset 15f3d0cc7660ee62c7a1c0420afaee18c26a2a1f by Yury Selivanov (Elvis Pranskevichus) in branch '3.7':
[3.7] bpo-32996: The bulk of What's New in Python 3.7 (GH-6978). (GH-6998)
https://github.com/python/cpython/commit/15f3d0cc7660ee62c7a1c0420afaee18c26a2a1f

New changeset 4d26c8a177d8ada440b3cfdfb1d0423ab5ca81a7 by Yury Selivanov (Elvis Pranskevichus) in branch 'master':
bpo-32996: Enhancements to What's New based on feedback (GH-7988)
https://github.com/python/cpython/commit/4d26c8a177d8ada440b3cfdfb1d0423ab5ca81a7

New changeset 48dc7527e32512a27a58107477926719ea4c589b by Miss Islington (bot) in branch '3.7':
bpo-32996: Enhancements to What's New based on feedback (GH-7988)
https://github.com/python/cpython/commit/48dc7527e32512a27a58107477926719ea4c589b

New changeset d47f0dd2e85ce032aebfedbde18cdb2e728fa79f by Ivan Levkivskyi (M. Eric Irrgang) in branch 'master':
bpo-32996: Documentation fix-up. (GH-16646)
https://github.com/python/cpython/commit/d47f0dd2e85ce032aebfedbde18cdb2e728fa79f

New changeset ca012360b103f2ab1acfa506aed032b0ed9b105c by Miss Islington (bot) in branch '3.7':
bpo-32996: Documentation fix-up. (GH-16646)
https://github.com/python/cpython/commit/ca012360b103f2ab1acfa506aed032b0ed9b105c

New changeset baf8a9b03a56ce1ee2284763b267ff56ab4507fe by Miss Islington (bot) in branch '3.8':
bpo-32996: Documentation fix-up. (GH-16646)
https://github.com/python/cpython/commit/baf8a9b03a56ce1ee2284763b267ff56ab4507fe

New changeset 49e650b2489da861d4c49b41787160f30d8259bf by Ned Deily (Miss Islington (bot)) in branch '3.7':
bpo-32996: Documentation fix-up. (GH-16646)
https://github.com/python/cpython/commit/49e650b2489da861d4c49b41787160f30d8259bf