Raffle docs

[mariopil]

Referenced issue

Closes #63 and closes #64

Summary of changes

Added Raffle contract documentation, fixed a bug related with buying a ticket after the raffle has been played.

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Name	Status	Preview	Comments	Updated (UTC)
eiger-nebula	✅ Ready (Inspect)	Visit Preview	💬 Add feedback	Sep 20, 2023 8:51am

[geofmureithi]

The markdown is still not correctly formatted. Well I think its because its blocked by #57

[mariopil]

What is wrong with it?

[geofmureithi]

I have the code highlighting tied to the #57 PR. Also the nebula-importer part would also need to be merged too to be valid. Maybe I should split it.