Well, you've not told us of flavor of web server so the following for apache and should work on any platform ... that's not remotely hosted. Is yours remotely hosted?
if you will NEVER use another app (ie server to be dedicated to Moodle alone ... forever), one could edit the document root and point directly to the moodle code directory. Example for CentOS/RHEL flavored servers:
document root as defined in httpd.conf is /var/www/html
one could change that to /var/www/html/moodle
This option requires restart of web service.
one could put an auto-forwarding index.html or index.php page at the current document root with 0 seconds wait time to forward.
Google is your friend here ... found one of perhaps thousands that tell/show how to:
No restart of web service for second option.
If remotely hosted, you should have some tool that allows one to point a domain to a folder. Dunno if a restart of web service needed or not.
'spirit of sharing', Ken