Improve homepage demo list

common/Cargo.toml

@@ -5,3 +5,4 @@ edition = "2021"
 
 [dependencies]
 serde = { version = "1", features = ["derive"] }
+chrono = { version = "0.4", features = ["serde"] }

common/src/lib.rs

@@ -2,6 +2,7 @@
 pub struct BaseDemoInfo {
     pub id: String,
     pub map: String,
+    pub uploaded_at: chrono::naive::NaiveDateTime,
     pub team2_score: i16,
     pub team3_score: i16,
 }