chore: fix credential rotation reference in readme (#25)

plugin/service/host/README.md

@@ -105,7 +105,7 @@ a configured IAM user for this provider:
 The following `attributes` are valid on an AWS host catalog resource:
 
 - `disable_credential_rotation` (bool): If `true`, credential rotation will not
-  be performed. See the [Credential Rotation](#credential-rotation) section
+  be performed. See the [Credential Rotation](../../../README.md#credential-rotation) section
   above.
 - `region` (string): The region to configure the host catalog for. All host sets
   in this catalog will be configured for this region.