💰 add sponsor section

README.md

@@ -19,6 +19,7 @@
 [![GitHub Sponsors](https://img.shields.io/badge/GitHub-Sponsors-ff69b4)](https://github.com/sponsors/nlohmann)
 
 - [Design goals](#design-goals)
+- [Sponsors](#sponsors)
 - [Integration](#integration)
   - [CMake](#cmake)
   - [Package Managers](#package-managers)
@@ -61,6 +62,17 @@ Other aspects were not so important to us:
 See the [contribution guidelines](https://github.com/nlohmann/json/blob/master/.github/CONTRIBUTING.md#please-dont) for more information.
 
 
+## Sponsors
+
+You can sponsor this library at [GitHub Sponsors](https://github.com/sponsors/nlohmann).
+
+### :label: Named Sponsors
+
+- [Michael Hartmann](https://github.com/reFX-Mike)
+
+Thanks everyone!
+
+
 ## Integration
 
 [`json.hpp`](https://github.com/nlohmann/json/blob/develop/single_include/nlohmann/json.hpp) is the single required file in `single_include/nlohmann` or [released here](https://github.com/nlohmann/json/releases). You need to add