Updating site to use USWDS styles (#509)

* Updated header and footer
* Updated fonts
* Moved files around and updated gulpfile to correct the build process when it goes to production
* Adjusted grid templating
* Added images to assets
* Update app/templates/components/uk_components/footer/template.njk

Co-authored-by: Steven Reilly <stvnrlly@users.noreply.github.com>

app/assets/js/uswds-init.js

@@ -0,0 +1,24 @@
+/* eslint-disable no-var */
+(function uswdsInit() {
+  "use strict";
+
+  var loadingClass = "usa-js-loading";
+  var fallback;
+
+  document.documentElement.classList.add(loadingClass);
+  function revertClass() {
+    document.documentElement.classList.remove(loadingClass);
+  }
+
+  fallback = setTimeout(revertClass, 8000);
+
+  function verifyLoaded() {
+    if (window.uswdsPresent) {
+      clearTimeout(fallback);
+      revertClass();
+      window.removeEventListener("load", verifyLoaded, true);
+    }
+  }
+
+  window.addEventListener("load", verifyLoaded, true);
+})();