Fix invalid JSON syntax in README configuration examples

[fal3]

Summary

• Fixed missing comma after "-y" in the npx args array (line 107)
• Changed code block language from bash to json for all JSON configuration examples
• Ensures all JSON samples in README are syntactically valid

Test plan

• Verified all JSON examples are valid JSON syntax
• Checked that syntax highlighting is now correct for JSON block

[Copilot]

Pull Request Overview

This PR fixes invalid JSON syntax in the README configuration examples by adding a missing comma in the npx arguments array and updating code block language tags to "json" for accurate syntax highlighting.

• Fixed missing comma in the npx arguments array.
• Updated code block language tags from "bash" to "json" for all JSON configuration examples.

[cameroncooke]

Thanks for this. I was changing this late last night. Admittedly I didn't test 🤦‍♂️