Revproxy is working. Added example cgi script

cgi-scripts/agena-cgi/src/main.rs

@@ -0,0 +1,15 @@
+use std::env;
+
+// Base url of agena proxy
+const BASE: &'static str = "gemini://example.com/";
+
+fn main() {
+    let query = match env::var("QUERY_STRING") {
+        Ok(q) => q,
+        _ => { 
+            println!("10\tGopher url:\r\n");
+            return;
+        },
+    };
+    println!("30\t{}{}\r\n", BASE, query);
+}