docs(reverseSecondHalf): fix subject

- fix some grammar issues and missing imports

subjects/reversesecondhalf/README.md

@@ -1,11 +1,11 @@
 ## reversesecondhalf
 
 ### Instructions
-Write a function that takes a `string` as an argument and prints the second half reversed. If the length of the string is odd, round it up.
+Write a function that takes a `string` as an argument and prints the second half reversed. If the length of the `string` is odd, round it up.
 
-- Print the second half reversed followed by newline `\n`.
-- If the string is empty, return `Invalid Output`.
-- If the string's length equals one, return it, followed by newline `\n`.
+- Print the second half reversed followed by a newline `\n`.
+- If the `string` is empty, return `Invalid Output`.
+- If the `string` length equals one, return it, followed by a newline `\n`.
 
 ### Expected function
 
@@ -22,12 +22,15 @@ Here is a possible program to test your function:
 ```go
 package main
 
-import "fmt"
+import (
+	"fmt"
+	"piscine"
+)
 
 func main() {
-	fmt.Print(ReverseSecondHalf("This is the 1st half This is the 2nd half"))
-	fmt.Print(ReverseSecondHalf(""))
-	fmt.Print(ReverseSecondHalf("Hello World"))
+	fmt.Print(piscine.ReverseSecondHalf("This is the 1st half This is the 2nd half"))
+	fmt.Print(piscine.ReverseSecondHalf(""))
+	fmt.Print(piscine.ReverseSecondHalf("Hello World"))
 }
 ```