Add Party color

[PeterTheOne]

Most of them use Purple or Orange. For creating designs it is important to know.

• Add a specification to PPI-party-info/doc/data_specification.md.
• Find and collect Data
• Add /data/ json files.

[collentine]

Believe this is too hard of an issue to gather. Some have an entire graphical manual whilst the majority have nothing... Recommend closing this issue unless we can think of a good solution for gathering data?

[PeterTheOne]

But still most parties have one main color.

[Putr]

The key can be added and be marked as optional.