Idea YARD/Warning

[ksss]

Simply notice YRAD warning on rubocop.

# @return Hash{Symbol => String}
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ [warn]: Invalid tag format for @return
def invalid_format(arg)
end

memo

def on_def(node)
  # ...
  io = StringIO.new
  log.reopen(io)
  parse(docstring)
  if !io.string.empty?
    add_offense(preceding_lines.last, message: io.string)
  end
end

ref: #26