fixed readme

Author: yangyin5127

README.md

@@ -2,3 +2,21 @@
 
 Simple SQL escape and format 
 
+
+## Escaping sql values
+
+```
+//Format
+sql := sqlstring.Format("select * from users where name=? and age=? limit ?,?", "t'est", 10, 10, 10)
+
+fmt.Printf("sql: %s",sql)
+
+//Escape
+sql = "select * from users WHERE name = " + sqlstring.Escape(name);
+fmt.Printf("sql: %s",sql)
+
+```
+
+## License
+
+MIT