fix: improve types of generated index.d.ts

[bartveneman]

No description provided.

[codecov-commenter]

Bundle Report

Changes will decrease total bundle size by 45 bytes (-0.02%) ⬇️. This is within the configured threshold ✅

Detailed changes

Bundle name	Size	Change
analyzeCss-esm	32.64kB	-45 bytes (-0.14%) ⬇️

Affected Assets, Files, and Routes:

view changes for bundle: analyzeCss-esm

Assets Changed:

Asset Name	Size Change	Total Size	Change (%)
css-*.js	-45 bytes	32.64kB	-0.14%

Files in css-*.js:

• ./src/context-collection.ts → Total Size: 935 bytes

• ./src/index.ts → Total Size: 30.11kB

• ./src/collection.ts → Total Size: 2.03kB