message: Document host attribute for github catalog provider.
  This was added in but isn't documented yet.
diff: @@ -96,6 +96,10 @@ catalog:
  topic:
  include: ['backstage-include'] # optional array of strings
  exclude: ['experiments'] # optional array of strings
  + enterpriseProviderId:
  + host: ghe.example.net
  + organization: 'backstage' # string
  + catalogPath: '/catalog-info.yaml' # string
  ```
  This provider supports multiple organizations via unique provider IDs.
  @@ -125,6 +129,8 @@ This provider supports multiple organizations via unique provider IDs.
  - **organization**:
  Name of your organization account/workspace.
  If you want to add multiple organizations, you need to add one provider config each.
  +- **host** _(optional)_:
  + The hostname of your GitHub Enterprise instance. It must match a host defined in [integrations.github](locations.md).
  ## GitHub API Rate Limits
  