readme.md: mention the kTLS/sendfile support

See #144

readme.md

@@ -1,7 +1,7 @@
 ## What is this?
 [![Docker Image CI](https://github.com/macbre/docker-nginx-http3/actions/workflows/dockerimage.yml/badge.svg)](https://github.com/macbre/docker-nginx-http3/actions/workflows/dockerimage.yml)
 
-Stable and up-to-date [nginx](https://nginx.org/en/CHANGES) with [QUIC + HTTP/3 support](https://nginx.org/en/docs/http/ngx_http_v3_module.html), [Google's `brotli` compression](https://github.com/google/ngx_brotli), [`njs` module](https://nginx.org/en/docs/njs/) and [Grade A+ SSL config](https://ssl-config.mozilla.org/)
+Stable and up-to-date [nginx](https://nginx.org/en/CHANGES) with [QUIC + HTTP/3 support](https://nginx.org/en/docs/http/ngx_http_v3_module.html), [Google's `brotli` compression](https://github.com/google/ngx_brotli), [`njs` module](https://nginx.org/en/docs/njs/), [kTLS/sendfile support](https://delthas.fr/blog/2023/kernel-tls/) and [Grade A+ SSL config](https://ssl-config.mozilla.org/)
 
 ## How to use this image
 As this project is based on the official [nginx image](https://hub.docker.com/_/nginx/) look for instructions there. In addition to the standard configuration directives, you'll be able to use the brotli module specific ones, see [here for official documentation](https://github.com/google/ngx_brotli#configuration-directives)