PR template a11y checklist item improvement (#79243)

.github/PULL_REQUEST_TEMPLATE.md

@@ -9,8 +9,9 @@ Delete any items that are not applicable to this PR.
 - [ ] Any text added follows [EUI's writing guidelines](https://elastic.github.io/eui/#/guidelines/writing), uses sentence case text and includes [i18n support](https://github.com/elastic/kibana/blob/master/packages/kbn-i18n/README.md)
 - [ ] [Documentation](https://www.elastic.co/guide/en/kibana/master/development-documentation.html) was added for features that require explanation or tutorials
 - [ ] [Unit or functional tests](https://www.elastic.co/guide/en/kibana/master/development-tests.html) were updated or added to match the most common scenarios
-- [ ] This was checked for [keyboard-only and screenreader accessibility](https://developer.mozilla.org/en-US/docs/Learn/Tools_and_testing/Cross_browser_testing/Accessibility#Accessibility_testing_checklist)
-- [ ] This renders correctly on smaller devices using a responsive layout. (You can test this [in your browser](https://www.browserstack.com/guide/responsive-testing-on-local-server)
+- [ ] Any UI touched in this PR is usable by keyboard only (learn more about [keyboard accessibility](https://webaim.org/techniques/keyboard/))
+- [ ] Any UI touched in this PR does not create any new axe failures (run axe in browser: [FF](https://addons.mozilla.org/en-US/firefox/addon/axe-devtools/), [Chrome](https://chrome.google.com/webstore/detail/axe-web-accessibility-tes/lhdoppojpmngadmnindnejefpokejbdd?hl=en-US))
+- [ ] This renders correctly on smaller devices using a responsive layout. (You can test this [in your browser](https://www.browserstack.com/guide/responsive-testing-on-local-server))
 - [ ] This was checked for [cross-browser compatibility](https://www.elastic.co/support/matrix#matrix_browsers)
 
 ### For maintainers