Organize code, begin database implementation

src/word.rs

@@ -0,0 +1,11 @@
+use chrono::{DateTime, Utc};
+use serde::Serialize;
+
+#[derive(Serialize)]
+#[serde(rename_all = "camelCase")]
+pub struct Word {
+    pub id: i64,
+    pub word: String,
+    pub reading: String,
+    pub timestamp: DateTime<Utc>,
+}