Use approved OpenJS footer (#2450)

Author: chrisgervang

website/docusaurus.config.js

@@ -164,8 +164,8 @@ const config = {
                 href: 'https://loaders.gl'
               },
               {
-                label: 'nebula.gl',
-                href: 'https://nebula.gl'
+                label: 'kepler.gl',
+                href: 'https://kepler.gl'
               }
             ]
           },
@@ -187,7 +187,7 @@ const config = {
             ]
           }
         ],
-        copyright: `Copyright © ${new Date().getFullYear()} OpenJS Foundation`
+        copyright: '<p>Copyright <a href="https://openjsf.org">OpenJS Foundation</a> and vis.gl contributors. All rights reserved. The <a href="https://openjsf.org">OpenJS Foundation</a> has registered trademarks and uses trademarks.  For a list of trademarks of the <a href="https://openjsf.org">OpenJS Foundation</a>, please see our <a href="https://trademark-policy.openjsf.org">Trademark Policy</a> and <a href="https://trademark-list.openjsf.org">Trademark List</a>.  Trademarks and logos not indicated on the <a href="https://trademark-list.openjsf.org">list of OpenJS Foundation trademarks</a> are trademarks&trade; or registered&reg; trademarks of their respective holders. Use of them does not imply any affiliation with or endorsement by them.</p><p><a href="https://openjsf.org">The OpenJS Foundation</a> | <a href="https://terms-of-use.openjsf.org">Terms of Use</a> | <a href="https://privacy-policy.openjsf.org">Privacy Policy</a> | <a href="https://bylaws.openjsf.org">Bylaws</a> | <a href="https://code-of-conduct.openjsf.org">Code of Conduct</a> | <a href="https://trademark-policy.openjsf.org">Trademark Policy</a> | <a href="https://trademark-list.openjsf.org">Trademark List</a> | <a href="https://www.linuxfoundation.org/cookies">Cookie Policy</a></p>'
       },
       prism: {
         theme: lightCodeTheme,