fix: fix doc for the wherein clause

- Missing parenthesis when using WhereIn on multiples columns
- Sprintf was not properly closed

README.md

@@ -1186,8 +1186,8 @@ Where(
 )
 
 // WHERE IN clause building
-WhereIn("name, age in ?", "John", 24, "Tim", 33) // Generates: WHERE ("name","age") IN (($1,$2),($3,$4))
-WhereIn(fmt.Sprintf("%s, %s in ?", models.PilotColumns.Name, models.PilotColumns.Age, "John", 24, "Tim", 33))
+WhereIn("(name, age) in ?", "John", 24, "Tim", 33) // Generates: WHERE ("name","age") IN (($1,$2),($3,$4))
+WhereIn(fmt.Sprintf("(%s, %s) in ?", models.PilotColumns.Name, models.PilotColumns.Age), "John", 24, "Tim", 33)
 AndIn("weight in ?", 84)
 AndIn(models.PilotColumns.Weight + " in ?", 84)
 OrIn("height in ?", 183, 177, 204)