docs: add governance parameter tuning guide

[gadst12]

Summary

Adds docs/governance-parameter-tuning.md — a guide explaining the effect of each governance parameter on DAO behaviour, the contract-enforced limits, recommended defaults by DAO size, and example configurations.

Changes

• docs/governance-parameter-tuning.md (new file, 249 lines)
  • Parameter definitions for quorum, duration, min_proposal_balance, proposal_cooldown, and restrict_admin_vote
  • Contract-enforced limits table: duration [60, 2 592 000], quorum (1 to total_supply), title [1, 128], description [1, 1024] — including the specific error variants raised
  • Recommended defaults for small/medium/large DAOs
  • Three example configurations: small DAO (fast/open), medium DAO (balanced), large DAO (conservative), and emergency proposals
  • Pass conditions formula and quorum interaction explanation
  • Monitoring metrics and adjustment guidance
  • References to lifecycle, storage, and DAO integration docs

Acceptance criteria

• Parameter definitions and tradeoffs are documented
• Recommended default values are suggested
• Example governance configurations are provided
• The guide references contract-enforced limits

Closes Vera3289#520