Add blog post for 4.0@rc1

[TimHess]

Additional news-related updates:

• add new post and the missing 3.2.2 post, remove 2 oldest
• don't need target=_blank
• add separation to list items

[github-actions]

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[bart-vmware]

Most of this document is written from the perspective of maintaining the Steeltoe codebase. While it's fine to mention in a side note all the quality improvements we did, the focus should be on why consumers benefit from updating to the new version. Such as new features, compatibility with the latest versions of .NET and key third-party products, NRT and API shape, schema completion, Docker images for testing, etc. Many of these we discussed in a presentation a few weeks ago.

And not to forget: improved security, no more vulnerable dependencies, etc.