DOC-1074: Update Zep credentials to medium tier template (n8n-io#2430)

Author: freakwriter

docs/integrations/builtin/credentials/zep.md

@@ -13,23 +13,41 @@ You can use these credentials to authenticate the following nodes:
 * [Zep](/integrations/builtin/cluster-nodes/sub-nodes/n8n-nodes-langchain.memoryzep/)
 * [Zep Vector Store](/integrations/builtin/cluster-nodes/root-nodes/n8n-nodes-langchain.vectorstorezep/)
 
-## Prerequisites
-
-Create a [Zep server](https://www.getzep.com/){:target=_blank .external-link} on the cloud or self-hosted with at least one project.
-
 ## Supported authentication methods
 
 - API key
 
 ## Related resources
 
-Refer to [Zep's Cloud SDK documentation](https://help.getzep.com/sdks){:target=_blank .external-link} and [Open Source SDK documentation](https://docs.getzep.com/sdk/){:target=_blank .external-link} for more information about the service.
+Refer to [Zep's Cloud SDK documentation](https://help.getzep.com/sdks){:target=_blank .external-link} and [Open Source SDK documentation](https://docs.getzep.com/sdk/){:target=_blank .external-link} for more information about the service. Refer to [Zep's REST API documentation](https://getzep.github.io/zep/){:target=_blank .external-link} for information about the API.
 
 --8<-- "_snippets/integrations/builtin/cluster-nodes/langchain-overview-link.md"
 
 ## Using API key
 
-To configure this credential, you'll need:
+To configure this credential, you'll need a [Zep server](https://www.getzep.com/){:target=_blank .external-link} with at least one project and:
+
+- An **API URL**
+- An **API Key**
+
+Setup depends on whether you're using Zep Cloud or self-hosted Zep Open Source.
+
+### Zep Cloud setup
+
+Follow these instructions if you're using [Zep Cloud](https://app.getzep.com){:target=_blank .external-link}:
+
+1. In Zep, open the [**Project Settings**](https://app.getzep.com/projects){:target=_blank .external-link}.
+2. In the **Project Keys** section, select **Add Key**.
+3. Enter a **Key Name**, like `n8n integration`.
+4. Select **Create**.
+5. Copy the key and enter it in your n8n integration as the **API Key**.
+6. Turn on the **Cloud** toggle.
+
+### Self-hosted Zep Open Source setup
+
+Follow these instructions if you're self-hosting [Zep Open Source](https://docs.getzep.com/deployment/quickstart/){:target=_blank .external-link}:
 
-- An **API URL**: For Cloud instances, enter `https://api.getzep.com`. For self-hosted instances, enter the URL for your Zep server.
-- An **API Key**: Generate a new API key from [**Project Settings**](https://help.getzep.com/projects){:target=_blank .external-link}.
+1. Enter the JWT token for your Zep server as the **API Key** in n8n.
+    - If you haven't generated a JWT token for your Zep server before, refer to Zep's [Configuring Authentication](https://docs.getzep.com/deployment/auth/){:target=_blank .external-link} for instructions.
+2. Make sure the **Cloud** toggle is off.
+3. Enter the URL for your Zep server as the **API URL**.