docs: add Slack channels for SDKs (#10270)

docs/api/index.md

@@ -127,16 +127,17 @@ Open-source contributors develop our SDKs, and more contributions are welcome to
 >
 > Also, remember to check the [API Reference Documentation](https://openfoodfacts.github.io/openfoodfacts-server/api/ref-v2/) first to verify if the problem is in SDK implementation or in the API itself.
 
-- [Cordova](https://github.com/openfoodfacts/openfoodfacts-cordova-app)
-- [Dart](https://github.com/openfoodfacts/openfoodfacts-dart/blob/master/DOCUMENTATION.md), published on [pub.dev](https://pub.dev/packages/openfoodfacts)
-- [Elixir](https://github.com/openfoodfacts/openfoodfacts-elixir)
-- [Go](https://github.com/openfoodfacts/openfoodfacts-go)
-- [NodeJS](https://github.com/openfoodfacts/openfoodfacts-nodejs)
-- [PHP](https://github.com/openfoodfacts/openfoodfacts-php)
-- [Laravel](https://github.com/openfoodfacts/openfoodfacts-laravel)
-- [Python](https://github.com/openfoodfacts/openfoodfacts-python), published on [pypi](https://pypi.org/project/openfoodfacts/)
-- [React Native](https://github.com/openfoodfacts/openfoodfacts-react-native)
-- [Ruby](https://github.com/openfoodfacts/openfoodfacts-ruby)
-- [Java](https://github.com/openfoodfacts/openfoodfacts-java)
-- [Rust](https://github.com/openfoodfacts/openfoodfacts-rust)
-- [R](https://github.com/openfoodfacts/r-dashboard)
+*   Cordova: [GitHub (old Open Food Facts official app)](https://github.com/openfoodfacts/openfoodfacts-cordova-app)
+*   DART: [GitHub](https://github.com/openfoodfacts/openfoodfacts-dart) - [Package on pub.dev](https://pub.dev/packages/openfoodfacts)
+*   Elixir: [GitHub](https://github.com/openfoodfacts/openfoodfacts-elixir) - [Discussion channel](https://app.slack.com/client/T02KVRT1Q/C758AFX0S)
+*   Go: [GitHub](https://github.com/openfoodfacts/openfoodfacts-go) - [Discussion channel](https://app.slack.com/client/T02KVRT1Q/C14LGGCUV)
+*   Java: [GitHub](https://github.com/openfoodfacts/openfoodfacts-java) - [Discussion channel](https://app.slack.com/client/T02KVRT1Q/C1G3J5RT3)
+*   Kotlin: [GitHub](https://github.com/openfoodfacts/openfoodfacts-kotlin) - [Discussion channel](https://app.slack.com/client/T02KVRT1Q/C045VU7NXS9)
+*   NodeJS: [GitHub](https://github.com/openfoodfacts/openfoodfacts-nodejs) - [Discussion channel](https://app.slack.com/client/T02KVRT1Q/C1JQQ28P8)
+*   PHP: [GitHub](https://github.com/openfoodfacts/openfoodfacts-php) - [Discussion channel](https://app.slack.com/client/T02KVRT1Q/C1G3GTJNM)
+*   PHP (Laravel): [GitHub](https://github.com/openfoodfacts/openfoodfacts-laravel) - [Discussion channel](https://app.slack.com/client/T02KVRT1Q/C1G3GTJNM)
+*   Python: [GitHub](https://github.com/openfoodfacts/openfoodfacts-python), published on [pypi](https://pypi.org/project/openfoodfacts/) - [Discussion channel](https://app.slack.com/client/T02KVRT1Q/C13993JDD)
+*   React Native: [GitHub](https://github.com/openfoodfacts/openfoodfacts-react-native) - [Discussion channel](https://app.slack.com/client/T02KVRT1Q/CL29QEBPY)
+*   Ruby: [GitHub](https://github.com/openfoodfacts/openfoodfacts-ruby) - [Discussion channel](https://app.slack.com/client/T02KVRT1Q/C0ZALLH61)
+*   Rust: [GitHub](https://github.com/openfoodfacts/openfoodfacts-rust) - [Discussion channel](https://app.slack.com/client/T02KVRT1Q/C010J616CKV)
+*   R: [GitHub](https://github.com/openfoodfacts/r-dashboard)