Proposing new process for documenting flags

What does this MR do?

This MR proposes new rules for documenting features behind feature flags. The reasons:

• Often our feature flag information is incorrect or out-of-date.
• More features are being developed behind flags and being released when the flag is removed, making the interim step of documenting the flag unnecessary.

The pros of this approach:

• Fewer incorrect flag statements
• Less work for writers/developers
• Less confusing for customers
• The flags are all auto-documented anyway

The cons:

• We won't be letting people know about features they might want to know about.

Related issues

Author's checklist

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