Release notes / changelog for v5.0.0 - no announcement for major version

Summary

azure-devops-extension-sdk 5.0.0 was published, but there is no public explanation of why it is a major version, what changed, or what might break for existing extensions.

This repo has no GitHub Releases, and the README still only documents the v4 major (ESM + AMD). There is no blog post, changelog, or migration guide that I could find.

Why this matters

Extension authors need to know:

1. Why the major bump (breaking changes vs. new capabilities only)
2. What changed in the public API / runtime behavior
3. Migration steps from 4.x → 5.x (if any)

Without that, teams cannot plan upgrades safely (especially for production Marketplace extensions).

Request

Please add at least one of:

• A GitHub Release for 5.0.0 with release notes
• A CHANGELOG.md (or README section) covering 5.0.0
• A short migration note: breaking changes, deprecations, and recommended SDK.init() / auth usage

Thanks — even a short bullet list of changes would unblock a lot of consumers.

Start by comparing the README’s v4 documentation with the published 5.0.0 package and reviewing the public API, runtime behavior, and SDK.init/auth usage. Done means adding a GitHub Release, CHANGELOG.md, or README section that explains the major-version rationale, changes, breaking behavior, deprecations, and migration steps from 4.x to 5.x.