typo fix for banner message

Author: FuhuXia

_includes/header.html

@@ -89,8 +89,8 @@
     </p>
 
     <p>
-      Archived content of Project Open Data can be access at its <a href="https://github.com/project-open-data/project-open-data.github.io">Github repository</a>.
-      You can report missing content or provide any additional feedback via <a href="https://github.com/GSA/resources.data.gov/issues">Github</a>
+      Archived content of Project Open Data can be accessed at its <a href="https://github.com/project-open-data/project-open-data.github.io">GitHub repository</a>.
+      You can report missing content or provide any additional feedback via <a href="https://github.com/GSA/resources.data.gov/issues">GitHub</a>
       or by emailing <a href="mailto:datagov@gsa.gov">datagov@gsa.gov</a>.
     </p>
   </div>