feat: add RandSliceFromGivenSlice function (#236)

docs/api/packages/random.md

@@ -26,6 +26,7 @@ import (
 -   [RandInt](#RandInt)
 -   [RandString](#RandString)
 -   [RandFromGivenSlice](#RandFromGivenSlice)
+-   [RandSliceFromGivenSlice](#RandSliceFromGivenSlice)
 -   [RandUpper](#RandUpper)
 -   [RandLower](#RandLower)
 -   [RandNumeral](#RandNumeral)
@@ -150,6 +151,33 @@ func main() {
 }
 ```
 
+### <span id="RandSliceFromGivenSlice">RandSliceFromGivenSlice</span>
+
+<p>从给定切片中生成长度为 num 的随机切片</p>
+
+<b>函数签名:</b>
+
+```go
+func RandSliceFromGivenSlice[T any](slice []T, num int, repeatable bool) []T
+```
+
+<b>示例:<span style="float:right;display:inline-block;">[运行]()</span></b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/random"
+)
+
+func main() {
+    	goods := []string{"apple", "banana", "cherry", "elderberry", "fig", "grape", "honeydew", "kiwi", "lemon","mango", "nectarine", "orange"}
+	chosen3goods := random.RandSliceFromGivenSlice(goods, 3, false)
+	fmt.Println(chosen3goods)
+}
+```
+
 ### <span id="RandUpper">RandUpper</span>
 
 <p>生成给定长度的随机大写字母字符串</p>