docs: add Blueprint codegen guide pagedocs: add Blueprint codegen guide page

[Laurel23]

Summary

This PR adds a dedicated guide page for the Blueprint module in the Evolution SDK.

Problem

Previously, the only available documentation for Blueprint was the auto-generated module reference. It lacked:

• Workflow explanation
• Codegen pipeline overview
• CodegenConfig option details
• Description of generated output
• Practical usage examples

This made Blueprint difficult for new users to understand and use.

Solution

Added a new guide page blueprint-codegen.mdx that includes:

• Step-by-step Blueprint workflow (Aiken → plutus.json → codegen → TypeScript bindings)
• Example usage code snippets
• Detailed CodegenConfig options table
• Description of generated artifacts
• Common pitfalls and tips

Impact

Improves developer onboarding and makes Blueprint one of the SDK’s primary entry points more accessible.

Closes #155