Reframe the external catalog entry to reflect the plugin's polyglot
test-generation pipeline (.NET/C#, Python, TypeScript/JavaScript, Java, Go,
Ruby, Rust, C++, Kotlin, Swift, PowerShell) and add polyglot keywords so
non-.NET developers can discover it. Mirrors the dotnet/skills 0.2.0 bump.
Edits the source (plugins/external.json) and regenerates the generated
.github/plugin/marketplace.json via npm run build. source stays unpinned
(tracks main), so no behavior change.
