add Chat struct

src/core/types.rs

@@ -9,3 +9,20 @@ pub struct User {
     username: Option<String>,
     language_code: Option<String>,
 }
+
+#[derive(Debug, Deserialize)]
+pub struct Chat {
+    id: i64,
+    chat_type: String,
+    title: Option<String>,
+    username:Option<String>,
+    first_name: Option<String>,
+    last_name: Option<String>,
+    photo: Option<ChatPhoto>,
+    description: Option<String>,
+    invite_link: Option<String>,
+    pinned_message: Option<Message>,
+    permissions: Option<ChatPermissions>,
+    sticker_set_name: Option<String>,
+    can_set_sticker_set: Option<Bool>,
+}