InsertBuilder, UpsertBuilder support write []byte (#77)

README.md

@@ -6,7 +6,15 @@
 
 a tool of sql query builder, build sql for sql.DB, [sqlx](https://github.com/jmoiron/sqlx), [gorp](https://github.com/go-gorp/gorp),
 or build condition sql for some orm framework, like [xorm](https://github.com/go-xorm/xorm), [gorm](https://github.com/go-gorm/gorm)....
-while ignore building of nil and empty string
+
+## Program feature:
+* ignore building of nil and empty string
+
+## Available field of struct:
+
+* base: string, *bool, *int64, *float64, time.Time....
+* json: struct, map, array, slice
+* bytes: []byte
 
 ## Example