Duplicated description for `<` and `<=` comparator rule functions

[aSemy]

The rules for both < and <= both say First argument is less than the second.

yaml-grammar/yaml-spec-1.2.yaml

Lines 257 to 261 in 1504782

	# * (<)
	# First argument is less than the second.
	#
	# * (<=)
	# First argument is less than the second.

I presume this is a mistake, and it should be:

  #   * (<)
  #     First argument is less than the second.
  #
  #   * (<=)
-  #     First argument is less than the second.
+  #     First argument is less than or equal to the second.