Port /newsletter from v1 (#566)

frontend/src/pages/newsletter/index.module.scss

@@ -0,0 +1,7 @@
+.emailInput {
+  max-width: 300px;
+}
+
+.emailForm {
+  padding: 15px;
+}

frontend/src/pages/newsletter/index.tsx

@@ -0,0 +1,56 @@
+import React from 'react'
+import { Button, Container, Form } from 'semantic-ui-react'
+
+import Page from '@components/Page'
+import styles from './index.module.scss'
+
+const Newsletter = () => (
+  <Page title="Kitspace Newsletter">
+    <Container>
+      <p>
+        Often people say to us: &quot;Wow that&apos;s a nice printed circuit board.
+        I would like to subscribe to your newsletter.&quot; Now you can! If
+        you&apos;re curious, you can read the latest edition first:{' '}
+        <a href="https://buttondown.email/kitspace/archive/kitspace-newsletter-1-assembling-projects/">
+          #1: Kitspace Newsletter #1: Assembling Projects.
+        </a>{' '}
+      </p>
+      <p>
+        Subscribe below, don&apos;t worry, it&apos;`s easy to unsubscribe if you
+        change your mind later. If you prefer, you can also{' '}
+        <a href="https://buttondown.email/kitspace/rss">subscribe via RSS</a>. If
+        you just want to get in touch email{' '}
+        <a href="mailto:info@kitspace.org">info@kitspace.org</a> instead.
+      </p>
+      <Form
+        action="https://buttondown.email/api/emails/embed-subscribe/kitspace"
+        className={styles.emailForm}
+        method="POST"
+        name="newsletter"
+      >
+        <input name="form-name" type="hidden" value="newsletter" />
+        <Form.Field>
+          <label>Your Email:</label>
+          <input
+            required
+            className={styles.emailInput}
+            name="email"
+            placeholder="you@example.com"
+            type="email"
+          />
+        </Form.Field>
+        <div hidden aria-hidden="true">
+          <label>
+            Don&apos;t fill this out if you&apos;re human:
+            <input name="bot-field" />
+          </label>
+        </div>
+        <Button primary type="submit">
+          Subscribe
+        </Button>
+      </Form>
+    </Container>
+  </Page>
+)
+
+export default Newsletter