[FrameworkBundle] Add alximy as backer of version 6.1

Author: nicolas-grekas

README.md

@@ -4,10 +4,27 @@ FrameworkBundle
 FrameworkBundle provides a tight integration between Symfony components and the
 Symfony full-stack framework.
 
+Sponsor
+-------
+
+The FrameworkBundle for Symfony 6.1 is [backed][1] by [alximy][2].
+
+A team of passionate humans from very different backgrounds, sharing their love of
+PHP, Symfony and its ecosystem. Their CTO, Expert developers, tech leads, can help
+you learn or develop the tools you need, and perform audits or tailored workshops.
+They value contributing to the Open Source community and are willing to mentor new
+contributors in their team or yours.
+
+Help Symfony by [sponsoring][3] its development!
+
 Resources
 ---------
 
  * [Contributing](https://symfony.com/doc/current/contributing/index.html)
  * [Report issues](https://github.com/symfony/symfony/issues) and
    [send Pull Requests](https://github.com/symfony/symfony/pulls)
    in the [main Symfony repository](https://github.com/symfony/symfony)
+
+[1]: https://symfony.com/backers
+[2]: https://alximy.io/
+[3]: https://symfony.com/sponsor