DEV-3206-new-go-exercice-string-to-bool (#1353)

* DEV-3206 add(docs):StringTobool readme

* DEV-3206 fix(docs):replace the example

* Update README.md

* docs(stringtobool): fix subject

- upgraded instructions
- fix 'expected function'
- add missing import 'piscine'
- fix white-spaces and indentation

* docs(stringtobool): fix typo

---------

Co-authored-by: Tiago Collot <collot.tiago1@gmail.com>
Co-authored-by: Michele Sessa <mikysett@gmail.com>

subjects/stringtobool/README.md

@@ -0,0 +1,46 @@
+## stringtobool
+
+### Instructions
+
+Write a function that takes a `string` as an argument and returns a `boolean`.
+
+- If the `string` equals `True`, `T` or `t` return `true`, otherwise return `false`.
+
+
+### Expected function
+
+```go
+func StringToBool(s string) bool {
+
+}
+```
+
+### Usage
+
+Here is a possible program to test your function:
+
+```go
+package main
+
+import (
+	"fmt"
+	"piscine"
+)
+
+func main() {
+	fmt.Println(piscine.StringToBool("True"))
+	fmt.Println(piscine.StringToBool("T"))
+	fmt.Println(piscine.StringToBool("False"))
+	fmt.Println(piscine.StringToBool("TTFF"))
+}
+```
+
+And its output:
+
+```console
+$ go run .
+true
+true
+false
+false
+```