Accept multiple dice groups

[Bernardo-MG]

Multiple dice groups could be supported.

They would be separated by commas: 1d6, 2d10+5

[Bernardo-MG]

This would have an impact on the returned object, as the parser would have to return a collection

[Bernardo-MG]

Related to 49. If the main parser returns a collection, or an aggregated root, then the transformers may be used to handle this as needed.

But it would still have an impact on the returns values.