feat(chat): add formatted timestamps with Timex

lib/slax_web/live/chat_room_live.ex

@@ -204,6 +204,7 @@ defmodule SlaxWeb.ChatRoomLive do
           <.link class="text-sm font-semibold hover:underline">
             <span><%= username(@message.user) %></span>
           </.link>
+          <span class="ml-1 text-xs text-gray-500"><%= message_timestamp(@message) %></span>
           <p class="text-sm"><%= @message.body %></p>
         </div>
       </div>
@@ -215,6 +216,10 @@ defmodule SlaxWeb.ChatRoomLive do
     user.email |> String.split("@") |> List.first() |> String.capitalize()
   end
 
+  defp message_timestamp(message) do
+    Timex.format!(message.inserted_at, "%-l:%M %p", :strftime)
+  end
+
   defp assign_message_form(socket, changeset) do
     assign(socket, :new_message_form, to_form(changeset))
   end