[pitivi-web] Explain what the tree-nation script does

[Alexandru Băluț <alexbalut src gnome org>]

commit 009a96db4fdee11b58c217b95d9c240e252e7cc5
Author: Alexandru Băluț <alexandru balut gmail com>
Date:   Sat Jul 31 23:15:51 2021 +0200

    Explain what the tree-nation script does

 layouts/partials/footer.html | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/layouts/partials/footer.html b/layouts/partials/footer.html
index 3c6d477..b86825d 100644
--- a/layouts/partials/footer.html
+++ b/layouts/partials/footer.html
@@ -38,8 +38,8 @@ piwikTracker.trackPageView();
 piwikTracker.enableLinkTracking();
 } catch( err ) {}
 </script>
-<!-- End Piwik Tag -->
 
 
+<!-- https://tree-nation.com/offset-website -->
 <script src="https://tree-nation.com/js/track.js";></script>
 <script>treenation_track("6104650b7213b");</script>
\ No newline at end of file