[DOC] - Document a release policy

[pavithraes]

Feature description

Document the decision-making process for conda-store libraries. Note:

• clearly mention we don't have a regular cadence, but a feature based approach
• distinction between important and urgent
• how we use milestones and "block-release" label
• process of creating a "requesting release" issue

Value and/or benefit

Communication about the development process for the development team, downstream development team, and end users.

Anything else?

No response