[instagram] allow disabling 'cursor' output

docs/configuration.rst

@@ -2392,6 +2392,24 @@ Description
     * ``"graphql"``: GraphQL API - lower-resolution media
 
 
+extractor.instagram.cursor
+--------------------------
+Type
+    * ``bool``
+    * ``string``
+Default
+    ``true``
+Example
+    ``"3414259811154179155_25025320"``
+Description
+    Controls from which position to start the extraction process from.
+
+    * ``true``: Start from the beginning.
+      Log the most recent ``cursor`` value when interrupted before reaching the end.
+    * ``false``: Start from the beginning.
+    * any ``string``: Start from the position defined by this value.
+
+
 extractor.instagram.include
 ---------------------------
 Type

gallery_dl/extractor/instagram.py

@@ -378,7 +378,11 @@ class InstagramExtractor(Extractor):
                                          "full_name": user["full_name"]})
 
     def _init_cursor(self):
-        return self.config("cursor") or None
+        cursor = self.config("cursor", True)
+        if not cursor:
+            self._update_cursor = util.identity
+        elif isinstance(cursor, str):
+            return cursor
 
     def _update_cursor(self, cursor):
         self.log.debug("Cursor: %s", cursor)