Create a repository trigger object for use in build triggers
cr_buildtrigger_repo(
  repo_name,
  branch = ".*",
  tag = NULL,
  type = c("github", "cloud_source"),
  github_secret = NULL,
  ...
)Either the GitHub username/repo_name or the Cloud Source repo_name
Regex of the branches that will trigger a build. Ignore if tag is not NULL
Regex of tags that will trigger a build
Whether trigger is GitHub or Cloud Source repoistory
If you need to pull from a private GitHub repo, add the github secret from Google Secret Manager which will be used via cr_buildstep_secret
Other arguments passed to either GitHubEventsConfig or RepoSource
Other BuildTrigger functions: 
BuildTrigger(),
GitHubEventsConfig(),
cr_buildtrigger_copy(),
cr_buildtrigger_delete(),
cr_buildtrigger_edit(),
cr_buildtrigger_get(),
cr_buildtrigger_list(),
cr_buildtrigger_pubsub(),
cr_buildtrigger_run(),
cr_buildtrigger_webhook(),
cr_buildtrigger()