update documentation

docs/example.nginx.conf

@@ -85,6 +85,11 @@ server {
         try_files $uri =404;
     }
 
+    location ^~ /block/ {
+        add_header Cache-Control max-age=0;
+        try_files $uri =404;
+    }
+
     location ^~ /datastore/ {
         add_header Cache-Control max-age=0;
         try_files $uri =404;