Make "end" only case opt-in

[azu]

Currently, report error for only start case like (
We want to report error for only end case like ).

NG

This is bad (.
This is bad (a].
This is bad ).

Current OK, but it should be error

This is bad ).
            ^ we want to check it

However, some user want to use 1).
So, we need to add new option to allow it as opt-in.
Or, it is just allow to use <number>)

textlint-rule-no-unmatched-pair/test/textlint-rule-no-unmatched-pair-test.js

Lines 30 to 36 in 95ef2df

	// FIXME: It will be failed
	// https://github.com/textlint-rule/textlint-rule-no-unmatched-pair/issues/1
	`
	1) item 1
	2) item 2
	3) item 3
	`,

[azu]

Maybe, It will be optional.

option name is just as well

{
  "checkEndBracket": true
}

1) item 1
2) item 2
3) item 3

I've received example case https://twitter.com/yasu_ja_jp/status/110258063909256397