DEVDOCS-6212

Applied the following revisions from an external review on the ticket:

* Added a paragraph calling out that the instructions are specifically for channel setup.
* Added a link to the b2b-buyer-portal repository for instructions on using the open source Buyer Portal.
* Removed callout about the invalid Vercel template.

Author: bc-Vince

docs/b2b-edition/headless.mdx

@@ -2,8 +2,10 @@
 
 B2B Edition's Buyer Portal can be used with headless storefronts created using a third-party solution, such as WordPress or Next.js. This allows you to extend B2B Edition's front-end buyer tools to multiple headless storefronts, while managing your back-end processes from the BigCommerce control panel.
 
+Follow the instructions in this article to set up a headless storefront channel that uses the default, hosted version of the Buyer Portal. If you want to deploy a locally-developed custom Buyer Portal to your headless channel, see the [Headless Guide](https://github.com/bigcommerce/b2b-buyer-portal/blob/main/docs/headless.md) in the b2b-buyer-portal repository. 
+
  <Callout type="info">
-  Use the following instructions to enable B2B Edition on non-Catalyst headless frameworks. See [B2B Edition](https://www.catalyst.dev/docs/b2b) for Catalyst-specific considerations.
+  These instructions are for enabling B2B Edition on non-Catalyst headless frameworks. See [B2B Edition](https://www.catalyst.dev/docs/b2b) for Catalyst-specific considerations.
  </Callout>
 
 <Steps>
@@ -48,10 +50,6 @@ X-Auth-Token: {{TOKEN_A}}
 }
 ```
 
- <Callout type="info">
-  Currently we’re working with [Vercel template, and that uses NextJS](https://github.com/B3BC/b2b-headless-example).
- </Callout>
-
  ### Generate an impersonation token
 
 [Generate an impersonation token](/docs/storefront-auth/tokens/customer-impersonation-token) by using the next cURL as base and using TOKEN_B.