docs(README): refine project description and clarify core functionality

Author: yarlson

README.md

@@ -1,12 +1,12 @@
-# Zero - Go ACME Client for ZeroSSL
+# Zero - SSL Certificate Manager
 
 ## Problem
 
 Nginx servers need SSL/TLS certificates for secure connections. Existing solutions like Certbot are often too large and complex for simple setups.
 
 ## Solution
 
-Zero is a lightweight Go ACME client for obtaining and renewing SSL/TLS certificates from ZeroSSL using the ACME protocol. It runs as a daemon, serving HTTP-01 challenges and automatically managing certificate renewals.
+Zero is a lightweight service that manages SSL/TLS certificates using ZeroSSL. It automatically handles certificate obtainment, renewal, and HTTP challenges while running as a background service.
 
 ## Features