Email: Send pledge confirmation with authentication token.

Fixes #34.
Fixes #10.

plugins/wporg-5ftf/views/form-pledge-confirm-email.php

@@ -0,0 +1,42 @@
+<?php
+
+namespace WordPressDotOrg\FiveForTheFuture\View;
+
+/**
+ * @var bool   $email_confirmed
+ * @var string $directory_url
+ */
+
+?>
+
+<?php if ( true === $email_confirmed ) : ?>
+
+	<div class="notice notice-success notice-alt">
+		<p>
+			Thank you for confirming your address! Your pledge will show up in <a href="<?php echo esc_url( $directory_url ); ?>">the directory</a> once one of your contributors confirms their participation.
+		</p>
+	</div>
+
+<?php else : ?>
+
+	<div class="notice notice-error notice-alt">
+		<p>
+			<?php
+			/*
+			 * There could be other reasons it failed, like an invalid token, but this is the most common reason,
+			 * and the only one that normal users should experience, so we're assuming it in order to provide
+			 * the best UX.
+			 */
+			?>
+			Your confirmation link has expired, please obtain a new one:
+		</p>
+
+		<p>
+			<button class="button-secondary">
+				<?php esc_html_e( 'Resend confirmation email', 'wporg' ); ?>
+				<?php // todo make ^ work when making the other 2 work ?>
+			</button>
+		</p>
+	</div>
+
+<?php endif; ?>