docs: add doc for Min, Max, and Average

docs/mathutil.md

@@ -20,9 +20,13 @@ import (
 <div STYLE="page-break-after: always;"></div>
 
 ## Index
+- [Average](#Average)
 - [Exponent](#Exponent)
 - [Fibonacci](#Fibonacci)
 - [Factorial](#Factorial)
+- [Max](#Max)
+- [Min](#Min)
+
 - [Percent](#Percent)
 - [RoundToFloat](#RoundToFloat)
 - [RoundToString](#RoundToString)
@@ -33,6 +37,35 @@ import (
 ## Documentation
 
 
+
+### <span id="Average">Average</span>
+<p>Return average value of numbers. Maybe call RoundToFloat to round result.</p>
+
+<b>Signature:</b>
+
+```go
+func Average[T lancetconstraints.Number](numbers ...T) T
+```
+<b>Example:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/mathutil"
+)
+
+func main() {
+	fmt.Println(mathutil.Average(0, 0)) //0
+	fmt.Println(mathutil.Average(1, 1)) //1
+	avg := mathutil.Average(1.2, 1.4) //1.2999999998
+	roundAvg := mmathutil.RoundToFloat(avg, 1) // 1.3
+}
+```
+
+
+
 ### <span id="Exponent">Exponent</span>
 <p>Calculate x to the nth power.</p>
 
@@ -117,6 +150,60 @@ func main() {
 
 
 
+### <span id="Max">Max</span>
+<p>Return max value of numbers.</p>
+
+<b>Signature:</b>
+
+```go
+func Max[T lancetconstraints.Number](numbers ...T) T
+```
+<b>Example:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/mathutil"
+)
+
+func main() {
+	fmt.Println(mathutil.Max(0, 0)) //0
+	fmt.Println(mathutil.Max(1, 2, 3)) //3
+	fmt.Println(mathutil.Max(1.2, 1.4, 1.1, 1.4)) //1.4
+}
+```
+
+
+
+### <span id="Min">Min</span>
+<p>Return min value of numbers.</p>
+
+<b>Signature:</b>
+
+```go
+func Min[T lancetconstraints.Number](numbers ...T) T
+```
+<b>Example:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/mathutil"
+)
+
+func main() {
+	fmt.Println(mathutil.Min(0, 0)) //0
+	fmt.Println(mathutil.Min(1, 2, 3)) //1
+	fmt.Println(mathutil.Min(1.2, 1.4, 1.1, 1.4)) //1.1
+}
+```
+
+
+
 ### <span id="Percent">Percent</span>
 <p>calculate the percentage of val to total, retain n decimal places.</p>