Revise rewards.mdx for Movement Network details

[cshein45]

Summary

Updated the rewards documentation to better align with Movement Network architecture and developer ecosystem.

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What changed? Why?

• Improved content structure for clarity and readability
• Added Movement Network context to Base rewards system
• Refined HTML/MDX layout for better presentation
• Organized sections to support developer onboarding

These changes ensure the rewards documentation reflects real use cases within the Movement ecosystem and improves understanding for builders.

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Notes to reviewers

• This is a documentation-only update (no contract or logic changes)
• Focused on structure, clarity, and ecosystem alignment
• No breaking changes

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How has it been tested?

• Verified MDX rendering locally / in preview
• Checked layout consistency and readability
• Confirmed all sections display correctly

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Additional context

This update prepares the rewards documentation for future integration with:

• DAO incentive systems
• On-chain identity tracking
• Builder reward mechanisms

[cb-heimdall]

🟡 Heimdall Review Status

Requirement	Status	More Info
Reviews	🟡 0/1	Denominator calculation Show calculation 1 if user is bot 0 1 if user is external 0 2 if repo is sensitive 0 From .codeflow.yml 1 Additional review requirements Show calculation Max 0 0 From CODEOWNERS 0 Global minimum 0 Max 1 1 1 if commit is unverified 0 Sum 1