message: [terminal] Adds convenience operator overload for Coordinate + Offset
diff: @@ -363,6 +363,11 @@ struct GridSize
  constexpr iterator end() noexcept { return iterator { columns, *columns * *lines }; }
  };
  +constexpr Coordinate operator+(Coordinate a, GridSize::Offset b) noexcept
  +{
  + return Coordinate { a.line + b.line, a.column + b.column };
  +}
  +
  constexpr GridSize::iterator begin(GridSize const& s) noexcept
  {
  return s.begin();
  