feat : Add devisors subject

subjects/divisors/README.md

@@ -0,0 +1,38 @@
+# Devisor
+
+### Instructions
+
+Write a function that takes a positive  integer and returns the number of it's devisors.
+- If the the number a is negative return 0.
+
+### Expected function
+```go
+func Divisors(n int) int {        
+    ...
+}
+```
+### Usage
+
+```go
+package main
+
+import (
+    "fmt"
+    "piscine"
+)
+
+func main() {
+    fmt.Println(piscine.Divisors(4))// 4 can be divided by 1 and 2 and 4
+    fmt.Println(piscine.Divisors(5))//5 can be divided by 1 and 5
+}
+
+```
+
+And its output :
+
+
+```console
+$ go run .
+3 
+2 
+```