Tasks to complete before releasing Steeltoe 4.0.0

[TimHess]

• Isolate integration test runs by branch Samples#278
• Update wiki page #1489
• Describe the meaning of branches/tags in /README.md #1550
• Public API diffs #1564
• Address Provide user guidance about merged packages #1242 and Make use of nuget depreciation warnings #1241
• Create Steeltoe GitHub release and publish new NuGet packages
• Merge changes from main branches into 4.x branches
• Search/replace branch names (and verify no broken links) in Samples, Documentation and MainSite
• If the JSON configuration schema has changed, create tag v4.0.0 in the Schema repository and deploy updated schema to https://steeltoe.io/schema/v4/schema.json
• Tag branches in samples/docs/schema after release, update README badges

[bart-vmware]

I'd like to suggest the following branch names:

• "main" in Steeltoe/Samples/Documentation/MainSite: ongoing development
• "release/2.x" and "release/3.x" in Steeltoe: the latest stable release, available for hotfixes (earlier releases can be identified by tag)
• "2.x" and "3.x" in Samples: source for linking to from documentation
• "release/latest" in Documentation/MainSite: what's deployed to steeltoe.io production ("main" deployed to staging dev.steeltoe.io)

Cross-links in main branches remain problematic. They need to be updated each time a major release ships.

Once these changes have been applied, we should run a tool like https://www.screamingfrog.co.uk/seo-spider/tutorials/broken-link-checker/ to discover broken links.

[TimHess]

We'll have to make some changes to the release process for Documentation/MainSite to account for the new strategy (along with potentially merging the documentation back into mainsite while updating docfx), but I agree with all of the above.

[bart-vmware]

See also: https://github.com/SteeltoeOSS/Steeltoe/wiki/Release-Process