message: Render annotated terms in GUI
diff: @@ -76,7 +76,11 @@ fn view_term<M: 'static>(term: &pikelet::core::Term) -> Element<M> {
  Term::Constant(Constant::Char(data)) => Text::new(format!("{:?}", data)).into(),
  Term::Constant(Constant::String(data)) => Text::new(format!("{:?}", data)).into(),
  Term::Sequence(_) => Text::new("todo").into(),
  - Term::Ann(_, _) => Text::new("todo").into(),
  + Term::Ann(term, r#type) => Row::new()
  + .push(view_term(term))
  + .push(Text::new(" : "))
  + .push(view_term(r#type))
  + .into(),
  Term::RecordTerm(_) => Text::new("todo").into(),
  Term::RecordType(_) => Text::new("todo").into(),
  Term::RecordElim(_, _) => Text::new("todo").into(),
  