chore: adopt create engine's 'new' mode

[JoshuaKGoldberg]

PR Checklist

• Addresses an existing open issue: fixes 🛠 Tooling: Use the create engine for initial/sample file creation #1754; fixes 🚀 Feature: Use the create engine for repository creation #1763
• That issue was marked as status: accepting prs
• Steps in CONTRIBUTING.md were taken

Overview

Corresponding create PR: JoshuaKGoldberg/create#48

Adds src/ directory creation as part of Block initialize()s. Hooks up mode: "new" for the new runtime mode setting. As a result, createStructure no longer needs a manual src: createSrc().

I've been testing this with:

gh repo delete JoshuaKGoldberg/cta-create-testing-1 --yes; rm -rf ./cta-*; CTA_CREATE_ENGINE=true node ~/repos/create-typescript-app/bin/index.js --base common --owner JoshuaKGoldberg --repository cta-create-testing-1 --title "CTA Create Testing" --description "Testing, will delete."; code cta-create-testing-1

💖

[github-actions]

🎉 This is included in version v1.77.1 🎉

The release is available on:

• GitHub releases
• npm package (@latest dist-tag)

Cheers! 📦🚀