fixing export file according to issue

subjects/ascii-art-web/export-file/README.md

@@ -13,6 +13,7 @@ Ascii-art-web-export consists on making sure that it is possible to export the o
 
 - The web server must export at least in one export format.
 - The web server must be created in **Go**.
+- The web site must include a button or a link to download/export the file.
 - You must handle website errors.
 - The code must respect the [good practices](../../good-practices/README.md).
 

subjects/ascii-art-web/export-file/audit.md

@@ -10,6 +10,8 @@
 
 ###### Are the exported files read and write for the user?
 
+###### Does the site include a link or a button to download the file?
+
 ###### Does the project use the HTTP header [Content-Type](https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Type) to indicate the media type of the resource?
 
 ###### Does the project use the HTTP header [Content-Length](https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Length) to indicate the size of the entity-body, in bytes, sent to the recipient?