Migrate JSDoc type definitions to TypeScript

[adamstankiewicz]

Some files rely on JSDoc-style type definitions despite the repository now having first-class support for TypeScript (e.g., in the paragonUtils.js file [soon to be merged, source link TBD]).'

To improve maintainability and confidence in future refactors, migrating these JSDoc type definitions to TypeScript would be beneficial.

Example JSDoc type definitions:

/**
 * @typedef {Object} ParagonThemeCssAsset
 * @property {string} filePath
 * @property {string} entryName
 * @property {string} outputChunkName
 */

### Tasks
- [ ] Migrate JSDoc-style type definitions to TypeScript.