Add anchor link

Author: libutcher

README.md

@@ -34,7 +34,7 @@ When managing items with 1Password SDKs, you must use [unique identifiers (IDs)]
 
 To use the 1Password Python SDK in your project:
 
-1. Provision your service account token. We recommend provisioning your token from the environment. For example, to export your token to the `OP_SERVICE_ACCOUNT_TOKEN` environment variable:
+1. Provision your [service account](#authentication) token. We recommend provisioning your token from the environment. For example, to export your token to the `OP_SERVICE_ACCOUNT_TOKEN` environment variable:
 
     **Mac**