Binary document format encoded as a file
----------------------------------------
This format defines the header and structure of files who contain
documents in binary form.
```
Bytes 0 4 8 X Y
+---+---+---+---+---+---+---+---+---+ - - - +---+---+ - - - +---+
|'D' 'B' 'N' ' '| 1 | DOCUMENT TYPE | DOCUMENT |
+---+---+---+---+---+---+---+---+---+ - - - +---+---+ - - - +---+
```
|Offset| Description |
|-----|----------------------------------------------------------------------------------------------------------|
| 0-4 | file format signature, ASCII value "DBN " with the ending space |
| 4-8 | 4 bytes unsigned integer in Little-Endian for the format version number, must be 1 |
| 8-X | document type encoded as a document, see document binary format |
| X-Y | document matching provided document type if provided, encoded as defined by the document binary format |