feat: add chat schema and migration

priv/repo/migrations/20241008234613_create_rooms.exs

@@ -0,0 +1,12 @@
+defmodule Slax.Repo.Migrations.CreateRooms do
+  use Ecto.Migration
+
+  def change do
+    create table(:rooms) do
+      add :name, :string, null: false
+      add :topic, :text
+
+      timestamps(type: :utc_datetime)
+    end
+  end
+end