Fix link to Splunk docs (#330)

Author: tothmano

endpoints/splunk.mdx

@@ -20,7 +20,7 @@ This page explains how to send data from Splunk to Axiom.
 
 In Splunk, specify the following environment variables:
 
-- `token` is your Splunk API token. For information, see the [Splunk documentation](https://docs.splunk.com/observability/en/admin/authentication/authentication-tokens/api-access-tokens.html).
+- `token` is your Splunk API token. For information, see the [Splunk documentation](https://help.splunk.com/en/splunk-observability-cloud/administer/authentication-and-security/authentication-tokens/api-access-tokens).
 - `url` or `host` is the target URL for the endpoint you have generated in Axiom by following the procedure above. For example, `https://opbizplsf8klnw.ingress.axiom.co`.
 
 ## Examples