1.6.0 (#390) * feat(next): implement entity revalidated event * chore(next): phpcs warnings hehe ci is working * docs(www): add documentation for on-demand revalidation * feat(basic-starter): add DRUPAL_REVALIDATE_SECRET variable * feat(graphql-starter): add DRUPAL_REVALIDATE_SECRET variable * docs(www): update docs for environment variables * fix(www): add redirect for /docs/on-demand-revalidation * docs(www): add next-drupal 1.6.0 blog post * docs(www): update blog post * feat(www): add new learn section * feat: implement rehype-pretty-code for blog pages