Update server name and root directory in nginx configuration

This commit updates the server name from localhost to portfolio.stitts.dev in the nginx configuration file. The root directory has also been modified, and an additional index file type, index.htm, has been added to the index instruction.

nginx.conf

@@ -1,9 +1,9 @@
 server {
     listen 80;
-    server_name localhost;
+    server_name portfolio.stitts.dev;
 
-    root /usr/share/nginx/site;
-    index index.html;
+    root /usr/share/nginx/site/;
+    index index.html index.htm;
 
     location / {
         try_files $uri $uri/ =404;