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/templates/views/user-profile.html

@@ -8,7 +8,7 @@
 
 {% block maincolumn_content %}
 
-  <h1 class="heading-large">Your profile</h1>
+  <h1 class="font-body-2xl margin-bottom-3">Your profile</h1>
 
   <div class="body-copy-table">
     {% call mapping_table(