feat: add README.md of new go exercise jumpover

subjects/jumpover/README.md

@@ -0,0 +1,43 @@
+# jumpover
+
+### Instructions
+
+Write a function `jumpover` that takes a string and returns another string with every third character.
+
+- Prints the output followed by newline `\n`.
+- If the string is empty, return newline `\n`.
+- If there is no third character, return newline `\n`.
+
+### Expected function
+
+```go
+func JumpOver(str string) string {
+}
+```
+
+### Usage
+
+Here is a possible program to test your function :
+
+```go
+package main
+
+import "fmt"
+
+func main() {
+    fmt.Print(JumpOver("1010101010"))
+    fmt.Print(JumpOver(""))
+    fmt.Print(JumpOver("t w e l v e"))
+    fmt.Print(JumpOver("12"))
+}
+```
+
+And its output :
+
+```go
+$ go run . | cat -e
+101$
+$
+w v$
+$
+```