DEVELOPER.md

Run:

• npm test to execute unit tests.
• npm run tdd or npm run tdd:ui to execute unit tests in the TDD mode (tests are re-run on each change).
• npm run build to build the lib
• npm run format:check to check that files are correctly formatted
• npm run format:fix to reformat files
• npm run api to run the api-extractor
• npm run docs to run api-documenter based on the api-extractor result. It will generate the tsdoc markdown files.