Name specification for the generated file

when ent init GoodsType
```
type GoodsType struct {
ent.Schema
}
```
the struct name is good , but the filename of generated go file name with scheme is "goodstype.go", and the name of file categories is the same as that which is a little bad for the name way.

I advice we can beautify the file name when the object name is a word group , we can also use "UnderScoreCase".

example:
goods_type.go
goods_type
goods_type_create.go
goods_type_delete.go

I wish you could understand my suggestion.