Add first-party support for TypeScript (type stripped) Configuration Files, Data Files, and Template Types

[zachleat]

From #3616 and #4007

In preparation for Node.js stable to ship TypeScript stripping as an unflagged feature https://nodejs.org/api/typescript.html

We already provide support for TypeScript via tsx, documented here: https://www.11ty.dev/docs/languages/typescript/

Default Configuration File Names

• eleventy.config.ts
• eleventy.config.mts
• eleventy.config.cts
• Not .tsx

Default Data File Names

• *.11tydata.ts
• *.11tydata.mts
• *.11tydata.cts
• Not .tsx

Default TypeScript Template File Names

• *.11ty.ts
• *.11ty.mts
• *.11ty.cts
• Not .tsx