Add ConvertAPI cred-only page (n8n-io#2859)

Author: imchairmanm

docs/integrations/builtin/credentials/convertapi.md

@@ -0,0 +1,28 @@
+---
+#https://www.notion.so/n8n/Frontmatter-432c2b8dff1f43d4b1c8d20075510fe4
+title: ConvertAPI credentials
+description: Documentation for the ConvertAPI credentials. Use these credentials to authenticate ConvertAPI in n8n, a workflow automation platform.
+contentType: [integration, reference]
+---
+
+# ConvertAPI credentials
+
+--8<-- "_snippets/integrations/builtin/credentials/cred-only-statement.md"
+
+## Supported authentication methods
+
+* API Token
+
+## Related resources
+
+Refer to [ConvertAPI's API documentation](https://docs.convertapi.com/docs/getting-started) for more information about the service.
+
+This is a credential-only node. Refer to [Custom API operations](/integrations/custom-operations.md) to learn more. View [example workflows and related content](https://n8n.io/integrations/convertapi/) on n8n's website.
+
+## Using API Token
+
+To configure this credential, you'll need a [ConvertAPI](https://www.convertapi.com/a/signin) account and:
+
+- An [**API Token**](https://docs.convertapi.com/docs/api-tokens) to authenticate requests to the service.
+
+Refer to [ConvertAPI's API documentation](https://docs.convertapi.com/docs/authentication) for more information about authenticating to the service.

mkdocs.yml

@@ -1004,6 +1004,7 @@ nav:
         - integrations/builtin/credentials/coda.md
         - integrations/builtin/credentials/cohere.md
         - integrations/builtin/credentials/contentful.md
+        - integrations/builtin/credentials/convertapi.md
         - integrations/builtin/credentials/convertkit.md
         - integrations/builtin/credentials/copper.md
         - integrations/builtin/credentials/cortex.md