Add chomp to IO#readline and IO#readlines

[sue445]

IO.readlines supports chomp argument and signature exists.

rbs/core/io.rbs

Lines 2764 to 2766 in 745943b

	# - IO.readlines(path, sep = $/, **opts) -> array
	# - IO.readlines(path, limit, **opts) -> array
	# - IO.readlines(path, sep, limit, **opts) -> array

rbs/core/io.rbs

Line 2813 in 745943b

def self.readlines: (String | _ToPath name, ?String sep, ?Integer limit, ?external_encoding: String | Encoding | nil, ?internal_encoding: String | Encoding | nil, ?encoding: String | Encoding | nil, ?textmode: boolish, ?binmode: boolish, ?autoclose: boolish, ?mode: String, ?chomp: boolish) -> ::Array[String]

IO#readline and IO#readlines likewise support the chomp argument.

rbs/core/io.rbs

Lines 1632 to 1634 in 745943b

	# - readline(sep = $/, chomp: false) -> string
	# - readline(limit, chomp: false) -> string
	# - readline(sep, limit, chomp: false) -> string

rbs/core/io.rbs

Lines 1645 to 1647 in 745943b

	# - readlines(sep = $/, chomp: false) -> array
	# - readlines(limit, chomp: false) -> array
	# - readlines(sep, limit, chomp: false) -> array

But this didn't exist in io.rbs, so I added.

[soutaro]

Thanks! 👏