docs: improve warning

README.md

@@ -53,6 +53,8 @@ $ PRODUCTION=true HOSTS="host1:host2:host3" DURATION=1s go run main.go
 {Home:/your/home Port:3000 IsProduction:true Hosts:[host1 host2 host3] Duration:1s}
 ```
 
+⚠️⚠️⚠️ **Attention:** _unexported fields_ will be ignored **ignored**.
+
 ## Supported types and defaults
 
 Out of the box all built-in types are supported, plus a few others that
@@ -94,8 +96,6 @@ If you set the `envExpand` tag, environment variables (either in `${var}` or
 `$var` format) in the string will be replaced according with the actual value
 of the variable.
 
-⚠️⚠️⚠️ **Unexported fields are ignored.** ⚠️⚠️⚠️
-
 ## Custom Parser Funcs
 
 If you have a type that is not supported out of the box by the lib, you are able