Update README.md

Geekhyt · web-flow · commit f263a105d5d0 · 2021-02-06T16:23:03.000+08:00
diff --git a/README.md b/README.md
@@ -45,3 +45,4 @@
 
 ## 回溯
 - [17. 电话号码的字母组合](https://github.com/Geekhyt/javascript-leetcode/issues/27)
+- [46. 全排列](https://github.com/Geekhyt/javascript-leetcode/issues/28)

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`@@ -45,3 +45,4 @@`
`45`	`45`
`46`	`46`	`## 回溯`
`47`	`47`	`- [17. 电话号码的字母组合](https://github.com/Geekhyt/javascript-leetcode/issues/27)`
	`48`	`+- [46. 全排列](https://github.com/Geekhyt/javascript-leetcode/issues/28)`