- Python: tree of python objects instead of tree of dicts

- Rust: more derives

README.md

@@ -9,7 +9,7 @@ use ome_metadata::Ome;
 
 let xml = read_to_string($file)?;
 let ome: Ome = xml.parse()?;
-let image = &ome.image.unwrap()[0];
+let image = &ome.image[0];
 println!("acquisition date: {:#?}", image.acquisition_date);
 ```
 
@@ -22,4 +22,4 @@ with open($file) as f:
 ome = Ome.from_xml(xml)
 image = ome.image[0]
 print(f"acquisition date: {image.acquisition_date}")
-```
+```