README

We're starting to use api-extractor for api reports. The saved versions are committed to reports/ directory, making it possible to track evolution of the public API.

Since api-extractor .d.ts rollups don't support declaration map, using these as published types break jump-to-definition in VS Code. Until declaration map rollups are implemented we compile public types with tsc --stripInternal, which requires marking exports as internal at the index.ts barrel file level if they need to be used in multiple files.