subject(Count-Negative):add readme

subjects/countnegative/README.md

@@ -0,0 +1,38 @@
+## count-negative
+
+### Instructions 
+
+Write a function that takes an array of integers and returns the number of negative numbers in the array.
+- If the array is empty, the function should return `0`.
+
+### Expected function 
+```go 
+func CountNegative(numbers []int) int {
+    // your code here
+}
+```
+
+### Usage 
+
+```go
+package main 
+
+import "fmt"
+
+func main(){
+    fmt.Println(CountNegative([]int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}))
+    fmt.Println(CountNegative([]int{-1, -2, -3, -4, -5, -6, -7, -8, -9, -10}))
+    fmt.Println(CountNegative([]int{}))
+    fmt.Println(CountNegative([]int{-1,2,0,-3}))
+}
+```
+
+and the output should be:
+
+```console
+$ go run . 
+0
+10
+0
+2
+```