:money_with_wings: add sponsor (#5156)

Signed-off-by: Niels Lohmann <mail@nlohmann.me>

README.md

diff --git a/README.md b/README.md
index 658f932..e275e95 100644
--- a/README.md
+++ b/README.md
@@ -81,6 +81,7 @@
 - [Martti Laine](https://github.com/codeclown)
 - [Paul Harrington](https://github.com/phrrngtn)
 - [Mercedes-Benz Group](https://github.com/mercedes-benz)
+- [Ryan McCaffery](https://github.com/mccaffers)
 
 ### :label: Named Sponsors