[garethsb]

• Replaces the Azure Pipelines build badge, which shows Microsoft's old pipeline, with the badge for this repository's GitHub Actions workflow on cpprest-lts. It shows failing while the macOS jobs fail (pplx task unwrapping does not propagate exceptions on macOS #29).
• Replaces the six per-repository Repology badges with Repology's packaging status badge, which lists every repository that packages cpprestsdk. Several of the old badges were out of date: vcpkg removed cpprestsdk in June 2026, Ubuntu 18.04 is out of support, and Repology lists no openSUSE Tumbleweed package.
• Rewrites "Contribute Back!" to say what this fork accepts, link this repository's issues, pull requests and Maintaining this fork for projects that depend on cpprestsdk #15, and point to the security policy.
• Points the issue tracker links in "Having Trouble?" and "Quick Links" at this repository, labels the FAQ and documentation links as the original project's wiki, and adds the security policy.

Co-authored-by: Gareth's 🤖 buddy