Rewrite HOME.md and Setup.md for external customer-facing audience

[charlesgreen]

Summary

HOME.md and Setup.md currently read as internal project documentation, explaining to developers how to set up the project internally. These files should instead be rewritten to read as external, customer-facing product documentation for SimplyCubed Code.

Details

• HOME.md should introduce SimplyCubed Code as a product from a customer's perspective rather than describing it as an internal project.
• Setup.md should explain how a customer can install and use SimplyCubed Code within their own environment, rather than describing internal developer setup steps.

Acceptance Criteria

• HOME.md reads as a product overview aimed at external customers.
• Setup.md provides clear installation/usage instructions for customers deploying SimplyCubed Code in their own environment.
• Internal-only developer details are removed or relocated as appropriate.