Summary: Cody Free, Pro, Enterprise Starter plan changes

Why It Matters: This change tells people about updates to Cody plans.

What Changed:

• A new message was added at the top about changes to Cody Free, Cody Pro, and Enterprise Starter plans.
• The "Get Cody for free" button was removed.
• The "Download for free" buttons were removed.
• The "Get started" buttons were removed.
• The "AI Editor Assistant" feature name was changed to "Coding Agent" in some places.
• The "Try Amp" button was added.
• The "Ready to accelerate how you build software? Create an account and get started with the most informed AI editor assistant." text was removed.