Website - code contributions policy

[niciliketo]

Document the policy around code and other contributions.

[niciliketo]

Would like to share any profits with contributors in a way that is

1. Transparent
2. Simple
3. Fair
   In that order

[niciliketo]

Policy should be set for a fixed period of time, with the option to improve it in the future.
Current idea
10% - charity donation
10% - admin costs
80% - split equally between everyone who contributed a merged PR in the last 3 months

... can we do better?