added homework and atachments

src/stdtype.rs

@@ -3,7 +3,7 @@ use serde::{Deserialize, Serialize};
 #[derive(Debug, Clone, Serialize, Deserialize)]
 #[serde(rename_all = "PascalCase")]
 pub struct StdType {
-    id: String,
-    abbrev: String,
-    name: String,
+    pub id: String,
+    pub abbrev: String,
+    pub name: String,
 }