fix: experimental_http3 moved under server.protocol to fix deprecation notice (#105)

Author: thePanz

docker/caddy/Caddyfile

@@ -1,5 +1,9 @@
 {
-    experimental_http3
+    servers {
+        protocol {
+            experimental_http3
+        }
+    }
 }
 
 {$SERVER_NAME}