Expose an alternative, add-on-aware read component and hooks.

Co-authored-by: Emma Indal <emma.indahl@gmail.com>
Co-authored-by: Camila Belo <camilaibs@gmail.com>
Co-authored-by: Otto Sichert <git@ottosichert.de>
Co-authored-by: Anders Näsman <andersn@spotify.com>

Signed-off-by: Eric Peterson <ericpeterson@spotify.com>

plugins/techdocs/package.json

@@ -72,6 +72,7 @@
     "@testing-library/react": "^12.1.3",
     "@testing-library/react-hooks": "^7.0.2",
     "@testing-library/user-event": "^14.0.0",
+    "@types/event-source-polyfill": "^1.0.0",
     "@types/dompurify": "^2.2.2",
     "@types/jest": "^26.0.7",
     "@types/node": "^16.11.26",