Typed Sass Styling (#69)

* Addresses issue #16 -
Add styles via sass and module imports
Adds typed scss imports via gatsby-plugin-sass.
Makes use of .d.scss file generated by gatsby-plugin-scss-typescript,
but avoids importing that directly while they work out issue in gatsby v3.

* adding vscode config for easier local debugging

client/src/components/J40footer.tsx

@@ -0,0 +1,17 @@
+import React from 'react';
+import { Footer } from '@trussworks/react-uswds';
+import {Link} from 'gatsby';
+
+const footerLinks = [
+    <Link to="/">Home</Link>
+];
+
+const J40Footer = () => {
+    return (
+        <>
+        <Footer primary={[]} secondary={footerLinks} />
+        </>
+    );
+};
+
+export default J40Footer;