feat: add join confirmation and mail templating

config/config.exs

@@ -89,6 +89,10 @@ config :mv, MvWeb.Endpoint,
 # at the `config/runtime.exs`.
 config :mv, Mv.Mailer, adapter: Swoosh.Adapters.Local
 
+# Default mail "from" address for transactional emails (join confirmation,
+# user confirmation, password reset). Override in config/runtime.exs from ENV.
+config :mv, :mail_from, {"Mila", "noreply@example.com"}
+
 # Configure esbuild (the version is required)
 config :esbuild,
   version: "0.17.11",