- [refactor] make it match the 15.4 adapter
 - [babel] add `babel-plugin-add-module-exports` and fully use ESM syntax
 - [deps] update `enzyme-adapter-utils`, `object.assign`, `object.values`, `prop-types`, `react-is`
 - [meta] use `npmignore` to autogenerate an npmignore file
 - [eslint] switch to `@babel/eslint-parser`, fix linting
 - [dev deps] update `@babel/cli`, `@babel/core`, `@babel/register`, `eslint`, `eslint-config-airbnb`, `eslint-config-airbnb-base`, `eslint-plugin-import`, `eslint-plugin-jsx-a11y`, `eslint-plugin-markdown`, `eslint-plugin-react`, `eslint-plugin-react-hooks`
 - [dev deps] update `safe-publish-latest`; use `prepublishOnly`