slightly improve README

README.md

@@ -9,6 +9,8 @@ It is designed with security in mind, so there are secure defaults, and there is
 
 Configuration of the allowlist is done for each http method separately using the Go regexp syntax. This allows fine-grained control over the allowed http methods.
 
+The source code is available on [GitHub: wollomatic/socket-proxy](https://github.com/wollomatic/socket-proxy).
+
 ## Getting Started
 
 ### Warning
@@ -19,6 +21,8 @@ You should know what you are doing. Accidentally exposing a Unix socket to the p
 
 The container image is available on [Docker Hub: wollomatic/socket-proxy](https://hub.docker.com/r/wollomatic/socket-proxy).
 
+Every socket-proxy image is signed with Cosign. The public key is available on [GitHub: wollomatic/socket-proxy/main/cosign.pub](https://raw.githubusercontent.com/wollomatic/socket-proxy/main/cosign.pub) and [https://wollomatic.de/socket-proxy/cosign.pub](https://wollomatic.de/socket-proxy/cosign.pub). Please refer to the [Security Policy](https://github.com/wollomatic/socket-proxy/blob/main/SECURITY.md) for more information.
+
 ### Allowing access
 
 Because of the secure-by-default design, you need to explicitly allow every access.