If you currently have a file accessible at
http://website.com/Folder/index.html and would like it to be where folks land when they go to
http://website.com/ there are a couple of options to pursue:
You can modify your web hosting through the member tool at
https://members.sonic.net/websites/hosting/dir/ to point to this new directory. If you have web content that isn't currently in
http://website.com/Folder/ this may be a bad option, as that other content wouldn't be available through your domain name any more.
You can redirect requests for
http://website.com/index.html to
http://website.com/Folder/index.html with a .htaccess file. Some information about using .htaccess is available at
https://wiki.sonic.net/wiki/.htaccess#H ... new_URI.3F
You can redirect requests for
http://website.com/index.html to
http://website.com/Folder/index.html by putting a meta refresh in. We don't have any instructions related to that method, but a web search for "meta refresh" should get you on your way.
Alternately you can simply move the index at
http://website.com/Folder/index.html to its parent directory. Download it to your computer with an FTP client and then put it back up in its new home. This may not work smoothly depending on how you referenced other files like images and such within the new index.html file.