fix(landing): rephrase skills banner tagline for general audience

[marc0olo]

Summary

• Removes "canister" from the skills banner tagline on the landing page
• Replaces ICP-specific jargon with plain language suitable for developers new to ICP
• Before: "Teach your AI agent canister patterns, API integrations, CLI commands, and deployment workflows so it ships working code instead of guessing."
• After: "Teach your AI coding agent the patterns, APIs, and deployment workflows it needs to build on ICP so it ships working code instead of guessing."

Sync recommendation

hand-written