allow creation of registry module via Github app

[dsa0x]

Description

This PR fixes a bug that prevented users from being able to create a registry module using a github app. As defined by our API docs, an organization is required for the endpoint. For gh_oauth provider, the organization is already in the context via the tfe_oauth_client resource, but it needs to be explicitly added when creating with github-app. The module is created in the provided organization

Testing plan

1. The test should pass.
2. Creating a module using the github app should succeed with a 201 status code

data "tfe_github_app_installation" "gha_installation" {
  name = "YOUR_GH_NAME"
}

resource "tfe_registry_module" "petstore" {
  organization_name = tfe_organization.foobar2
  vcs_repo {
    display_identifier = "GH_NAME/REPO_NAME"
    identifier         = "GH_NAME/REPO_NAME"
    github_app_installation_id     = data.tfe_github_app_installation.gha_installation.id
  }
}

External links

• Ticket

[nfagerlund]

OK, this is good! I tested it out and it behaved as expected, and the code makes sense.

There's one doc typo, after which this is mergeable.