feat: Rich Text Rendering (#13)

* add text

* fix avatar is not show

* refactor chats

* improve rich text

* add benchmark for text

* update

crates/chats/src/message.rs

@@ -0,0 +1,57 @@
+use common::{last_seen::LastSeen, profile::NostrProfile};
+use gpui::SharedString;
+use nostr_sdk::prelude::*;
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct Message {
+    pub id: EventId,
+    pub content: String,
+    pub author: NostrProfile,
+    pub mentions: Vec<NostrProfile>,
+    pub created_at: LastSeen,
+}
+
+impl Message {
+    pub fn new(
+        id: EventId,
+        content: String,
+        author: NostrProfile,
+        mentions: Vec<NostrProfile>,
+        created_at: Timestamp,
+    ) -> Self {
+        let created_at = LastSeen(created_at);
+
+        Self {
+            id,
+            content,
+            author,
+            mentions,
+            created_at,
+        }
+    }
+}
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum RoomMessage {
+    /// User message
+    User(Box<Message>),
+    /// System message
+    System(SharedString),
+    /// Only use for UI purposes.
+    /// Placeholder will be used for display room announcement
+    Announcement,
+}
+
+impl RoomMessage {
+    pub fn user(message: Message) -> Self {
+        Self::User(Box::new(message))
+    }
+
+    pub fn system(content: SharedString) -> Self {
+        Self::System(content)
+    }
+
+    pub fn announcement() -> Self {
+        Self::Announcement
+    }
+}