Make repeatable as a Token

[hedhyw]

1. Idea

   type Repeatable struct {
      Token dialect.Token
      Suffix string
   }
   
   newRepeatable(token dialect.Token) // Default Suffix is `""`.
   
   OneOrMore() // And others should return `dialect.Token`.

   WriteTo -> Token than Suffix.

2. ClassRepetable

type ClassRepetable struct {
   dialect.ClassToken
   Repeatable
}

3. Return ClassRepetable for all Chars.* and for Common.Raw.