FM Program/JSSv3: Create table to list all database sources, what they do/don't provide & how they are accessed

[mochet]

SSIA There are ~3~ 4 sources currently, each provides something but not everything required.

Sources

• [ ] Airtable
• [ ] Notion Incentives Grading Database
• [ ] Query Node/GraphQL (on-chain data)
• [ ] Joystreamstats (reports and other such data generated by automated scripts)

What to list

• [ ] How to access each + links to documentation / tutorials
• [ ] A basic categorization of what data it provides
• [ ] Who controls each data source
• [ ] Any known restrictions (API limits, known difficulties with accessing data)