[Typo] Fix multiple wrong single and double quotation marks between 04.6 to 06.9

eBook/05.6.md

@@ -86,10 +86,10 @@ i := 0
 for { //since there are no checks, this is an infinite loop
 	if i >= 3 { break }
 	//break out of this for loop when this condition is met
-	fmt.Println(“Value of i is:”, i)
+	fmt.Println("Value of i is:", i)
 	i++;
 }
-fmt.Println(“A statement just after for loop.”)
+fmt.Println("A statement just after for loop.")
 ```
 
 2.
@@ -97,7 +97,7 @@ fmt.Println(“A statement just after for loop.”)
 ```go
 for i := 0; i<7 ; i++ {
 	if i%2 == 0 { continue }
-	fmt.Println(“Odd:”, i)
+	fmt.Println("Odd:", i)
 }
 ```