Auto-generate rollable tables from SRD

[BTMorton]

Now the SRD has been parsed and processed into a usable JSON format, we should be able to auto-generate the rollable tables from it. If we look for dX as the first key field in the table object, that indicates we have a table that can be rolled on.

This might require some updates to the table so that it can support X-Y roll types (e.g. on a d100, values for 60-75 and 75-80)