Public Engagement Page (#1372)

* Add public engagement page

- modifies sitemap config
- creates PublicEvent component
- adds SVGs for dates
- all copy is in intl

* Add Public Engagement button to each page

- create new PublicEng component
- add to each page
- update snapshots
- modify CEJST and Meth page to give button more space

* Make mobile compliant and fix DOM validation error

- transform each <p>'s descendent into a <CollectionDescription>
- fix a mobile rendering issue with <Collection> library
- format registration links so they render on mobile
- update snapshots

* Add spacing to descriptions and fix links

* Add Gherkin tests for testing links

- all zoom links should be functional
- ensure all legacy tests, test the new page
- add data-cy tag for cypress
- update snapshots

* Refactor to pass accessibility on all pages

- update snapshots

* Correct registration links

* Make registration links into buttons

* Make new tag bold

* Update copy based on feedback from Corey

client/src/components/PublicEngageButton/PublicEngageButton.tsx

@@ -0,0 +1,28 @@
+import React from 'react';
+import {Link} from 'gatsby';
+import {useIntl} from 'gatsby-plugin-intl';
+import {Button, Tag} from '@trussworks/react-uswds';
+
+import * as styles from './PublicEngageButton.module.scss';
+import * as PUBLIC_ENG_COPY from '../../data/copy/publicEngage';
+
+const PublicEngageButton = () => {
+  const intl = useIntl();
+
+  return (
+    <div className={styles.container}>
+      <div className={styles.tagContainer}>
+        <Tag className={styles.tag}>
+          {intl.formatMessage(PUBLIC_ENG_COPY.PUBLIC_ENG_BUTTON.TAG_LABEL)}
+        </Tag>
+      </div>
+      <Link className={styles.link} to={'/public-engagement'}>
+        <Button type={'button'} icon={true}>
+          {intl.formatMessage(PUBLIC_ENG_COPY.PUBLIC_ENG_BUTTON.LABEL)}
+        </Button>
+      </Link>
+    </div>
+  );
+};
+
+export default PublicEngageButton;