Site content and style update for sprint2/3 (#279)

* add legend and styling for map page
* update header to latest style/content
* add contact page
* add methodology page
#199 and #200

client/src/components/HowYouCanHelp.tsx

@@ -5,7 +5,7 @@ const HowYouCanHelp = () => {
   return (
     <div className={styles.howYouCanHelpContainer}>
       <h2>How You Can Help Improve the Tool</h2>
-      <ul>
+      <ul className={'usa-list'}>
         <li>If you have information that could help, we’d love to hear from you.</li>
         <li>View our full set of data sources and methodology
             where you can add or download sources and check statuses on our data roadmap.</li>