fix(interlink): add pairing key info

Author: RoRoJ

network/interlink/reference-content/provisioning.mdx

@@ -62,6 +62,8 @@ After ordering the InterLink from Scaleway, you **must** contact your chosen par
 
 Use the [Get a partner](https://www.scaleway.com/en/developers/api/interlink/#path-partners-get-a-partner) endpoint to get information about your selected partner. Each partner provides either a contact email address, and/or the URL of their online portal. You should make contact with your partner via one of these channels.
 
+You should also provide the partner with your unique [pairing key](/network/interlink/concepts/#pairing-key), which you can get via the [Get an InterLink](https://www.scaleway.com/en/developers/api/interlink/#path-links-get-a-link) endpoint.
+
 Your InterLink will remain in `Requested` status until the partner responds to your request.
 
 ### 3. Partner accepts InterLink request