Add <Heading> component

[MAILPOET-2770]

assets/js/src/common/typography/heading/heading.tsx

@@ -0,0 +1,19 @@
+import React from 'react';
+
+type Props = {
+  children: React.ReactNode,
+  level: 1 | 2 | 3 | 4 | 5,
+};
+
+const Heading = ({
+  children,
+  level,
+}: Props) => (
+  React.createElement(
+    `h${level}`,
+    undefined,
+    children
+  )
+);
+
+export default Heading;