Add comment to link to our gitlab in the html

src/Paste/Homepage.hs

@@ -26,7 +26,7 @@ import Paste.Styles
 -- | The homepage that serves as an instruction manual, and a post page for
 -- people using browsers.
 homepage :: Text -> Html
-homepage url = docTypeHtml ! lang "en" $ do
+homepage url = (docTypeHtml ! lang "en" $ do
     H.head $ do
              H.title "GnuPaste"
              H.style (toHtml stylesheet)
@@ -93,5 +93,7 @@ homepage url = docTypeHtml ! lang "en" $ do
 
 	     homepageJS
 
+  ) >> preEscapedToHtml ("\n\n<!-- https://gitlab.gnugen.ch/gnugen/gnupaste/ -->"::Text)
+
 homepageJS :: Html
 homepageJS = script $ toHtml $ decodeUtf8 $(embedFile "src/Paste/homepage.js")