credentials-export-domain: save cursor for next execution

Author: aviau

docs/guides/credentials-export-domain.mdx

@@ -40,19 +40,18 @@ These are end-to-end examples in various programming languages.
 <Accordion title="Python SDK Example">
 ```python
 import csv
-import os
 import sys
 import time
 
 from flareio import FlareApiClient
 
 
-api_client = FlareApiClient(
-    api_key=os.environ["FLARE_API_KEY"],
-)
+api_client = FlareApiClient.from_env()
 
 domain_name: str = "scatterholt.com"
-from_: str | None = None
+
+# The cursor from which we are starting the current execution.
+last_from: str | None = None
 
 writer = csv.DictWriter(
     sys.stdout,
@@ -71,7 +70,7 @@ for resp in api_client.scroll(
             "type": "domain",
             "fqdn": "scatterholt.com",
         },
-        "from": from_,
+        "from": last_from,
     },
 ):
     # Print results
@@ -85,8 +84,13 @@ for resp in api_client.scroll(
             },
         )
 
+    # Save the cursor for the next execution
+    last_from = resp.json().get("next") or last_from
+
     # Rate limiting.
     time.sleep(0.25)
+
+print(f"The next execution could resume using {last_from=}.")
 ```
 </Accordion>