feat: add vowels-index

subjects/vowels-index/README.md

@@ -0,0 +1,24 @@
+# VowlsIndex
+
+### Instructions
+
+- Write a function that takes one argument of type string and returns an array of intergers containing the index of the vowels in the string.
+- vowels : [a,i ,e ,u o]
+
+### Expected function
+
+```go 
+func VowelIdx(str string) []int {
+}
+```
+### Usage
+
+```console
+$ go run . "hello Iyan"
+$2
+$5
+$7
+$8
+$9
+```
+