Merge branch 'site_bkg' into 'main'

Website background

See merge request !39

assets/style.css

@@ -12,6 +12,8 @@ body {
   width: 50%;
   margin: auto;
   padding: 0;
+  background-image: url('../image/bkg.gif');
+  background-size: cover;
 }
 
 h1 {