pinterest: implement image and gifs support (#475)

Co-authored-by: jj <log@riseup.net>
Co-authored-by: wukko <me@wukko.me>

src/modules/processing/servicesConfig.json

@@ -91,7 +91,7 @@
             "enabled": true
         },
         "pinterest": {
-            "alias": "pinterest videos & stories",
+            "alias": "pinterest (all media)",
             "patterns": ["pin/:id", "pin/:id/:garbage", "url_shortener/:shortLink"],
             "enabled": true
         },