chore: update readme

README.md

@@ -40,7 +40,7 @@ int main(void) {
 }
 ```
 
-3. Build and cmeta
+3. Build and run cmeta
 
 ```console
 $ gcc cmeta.c -o cmeta
@@ -66,4 +66,12 @@ int main(void) {
 }
 ```
 
-It runs `gcc -E`, so it process everything your code uses, including structs from cmeta itself.
+```console
+$ gcc main.c -o main
+$ ./main
+My_Struct.name = My_Struct
+My_Struct.fields_count = 2
+```
+
+> [!NOTE]
+> It runs `gcc -E`, so it handles macros etc.