[Documentation][Deployments] Document & version [schema & deployment] "migration steps" inside README

[idiom-bytes]

Problem statement

As part of the deployment process right now (Local Airtable -> Staging Airtable -> Prod Airtable), there are various PR's being merged into main, that will eventually get integrated into VM (Prod).

As these changes are integrated, the Main branch should contain all required steps required, to deploy into Prod.

• VM is using Prod Airtable
• All PR's are using Staging Airtable
• Main branch then represents everything that needs to get deployed.

Examples of where this is applicable:

• Add OPS column in [Funding Round] Table
• Add new Proposal Standing enumerators or other single-select options.

Towards solutions

• Document/Version Airtable schema changes inside README
• Deployment can understand these changes / follow deployment steps
• Downstream consumers / Integrations (Pearl) can understand these changes