[unsplash] add 'format' option (#1197)

docs/configuration.rst

@@ -1600,6 +1600,19 @@ Description
     * ``false``: Skip video Tweets
 
 
+extractor.unsplash.format
+-------------------------
+Type
+    ``string``
+Default
+    ``"raw"``
+Description
+    Name of the image format to download.
+
+    Available formats are
+        ``"raw"``, ``"full"``, ``"regular"``, ``"small"``, and ``"thumb"``.
+
+
 extractor.vsco.videos
 ---------------------
 Type

gallery_dl/extractor/unsplash.py

@@ -27,10 +27,11 @@ class UnsplashExtractor(Extractor):
         self.item = match.group(1)
 
     def items(self):
+        fmt = self.config("format") or "raw"
         for photo in self.photos():
             util.delete_items(
                 photo, ("current_user_collections", "related_collections"))
-            url = photo["urls"]["raw"]
+            url = photo["urls"][fmt]
             text.nameext_from_url(url, photo)
 
             photo["extension"] = "jpg"