* housekeeping: `.js` -> `.jsx` where necessary

* `test/e2e` -> `test/e2e-selenium`

* add Cypress

* ESLint fixes

* MOAR cypress

* `integration` -> `tests`

* wire Cypress up to a hot e2e server

* linter fixes

* don't run in CI

* v3.17.6

* release(3.17.6): rebuild dist

* add failing tests

* fix Link component

* fix OnlineValidatorBadge component

* switch from <a> to <Link> in operation components

* make Markdown inputs safe

* use Link component in Info block, for target safety

* add eslint rule for unsafe `target` usage

preventative measure!