TS errors due to missing file extensions

[caugner]

The published web-features package includes TypeScript type declaration files that use imports without file extensions.

This causes TypeScript errors when using strict: true (and skipLibCheck: false).

See: https://github.com/caugner/web-features-test

Error: node_modules/web-features/index.d.ts(1,32): error TS2307: Cannot find module './types.quicktype' or its corresponding type declarations.
Error: node_modules/web-features/index.d.ts(2,27): error TS2834: Relative import paths need explicit file extensions in ECMAScript imports when '--moduleResolution' is 'node16' or 'nodenext'. Consider adding an extension to the import path.
Error: node_modules/web-features/index.d.ts(2,59): error TS2834: Relative import paths need explicit file extensions in ECMAScript imports when '--moduleResolution' is 'node16' or 'nodenext'. Consider adding an extension to the import path.
Error: node_modules/web-features/index.d.ts(2,96): error TS2834: Relative import paths need explicit file extensions in ECMAScript imports when '--moduleResolution' is 'node16' or 'nodenext'. Consider adding an extension to the import path.
Error: node_modules/web-features/index.d.ts(4,27): error TS2307: Cannot find module './types.quicktype' or its corresponding type declarations.
Error: node_modules/web-features/index.d.ts(6,27): error TS2307: Cannot find module './types.quicktype' or its corresponding type declarations.

(This affects mdn/browser-compat-data, where we currently skipLibCheck: true.)

[caugner]

I think the project is incorrectly using module: ESNext and moduleResolution: bundler.

See: https://www.typescriptlang.org/tsconfig/#module

You very likely want "nodenext" for modern Node.js projects and preserve or esnext for code that will be bundled.

[ddbeck]

Thanks, @caugner. Bug confirmed. Assigning this to myself, to see to it that the two PRs to clean this up get merged. Cheers!