docs: clarify repo_owner parameter semantics

- Since "repo" is somewhat overloaded, clarify that it refers to the
  owner of the repository in the git forge.
- Describe behavior of the `repo_owner` param in Gitlab's hierarchical ownership
- Fix bug in examples for params `repo_url` and `source_url`

Author: aThorp96

docs/content/docs/guide/authoringprs.md

@@ -55,13 +55,13 @@ check out the code that is being tested.
 | headers             | The request headers (see [below](#using-the-body-and-headers-in-a-pipelines-as-code-parameter))                                                                                 | `{{headers['x-github-event']}}`     | push                                                                                                                                                          |
 | pull_request_number | The pull or merge request number, only defined when we are in a `pull_request` event or push event occurred when pull request is merged.                                        | `{{pull_request_number}}`           | 1                                                                                                                                                             |
 | repo_name           | The repository name.                                                                                                                                                            | `{{repo_name}}`                     | pipelines-as-code                                                                                                                                             |
-| repo_owner          | The repository owner.                                                                                                                                                           | `{{repo_owner}}`                    | openshift-pipelines                                                                                                                                           |
-| repo_url            | The repository full URL.                                                                                                                                                        | `{{repo_url}}`                      | https:/github.com/repo/owner                                                                                                                                  |
+| repo_owner          | The repository owner in the git provider. (For VCS providers with owner hierarchies, e.g. GitLab's orgs; namespaces; groups; and subgroups, the full ownership slug is used)    | `{{repo_owner}}`                    | openshift-pipelines                                                                                                                                           |
+| repo_url            | The repository full URL.                                                                                                                                                        | `{{repo_url}}`                      | https:/github.com/openshift-pipelines/pipelines-as-code                                                                                                       |
 | revision            | The commit full sha revision.                                                                                                                                                   | `{{revision}}`                      | 1234567890abcdef                                                                                                                                              |
 | sender              | The sender username (or account ID on some providers) of the commit.                                                                                                            | `{{sender}}`                        | johndoe                                                                                                                                                       |
 | source_branch       | The branch name where the event comes from.                                                                                                                                     | `{{source_branch}}`                 | main                                                                                                                                                          |
 | git_tag             | The Git tag pushed (only available for tag push events; otherwise empty `""`).                                                                                                  | `{{git_tag}}`                       | v1.0                                                                                                                                                          |
-| source_url          | The source repository URL from where the event comes (same as the value `repo_url` for push events).                                                                            | `{{source_url}}`                    | https:/github.com/repo/owner                                                                                                                                  |
+| source_url          | The source repository URL from where the event comes (same as the value `repo_url` for push events).                                                                            | `{{source_url}}`                    | https:/github.com/openshift-pipelines/pipelines-as-code                                                                                                       |
 | target_branch       | The branch name on which the event targets (same as `source_branch` for push events).                                                                                           | `{{target_branch}}`                 | main                                                                                                                                                          |
 | target_namespace    | The target namespace where the Repository has matched and the PipelineRun will be created.                                                                                      | `{{target_namespace}}`              | my-namespace                                                                                                                                                  |
 | trigger_comment     | The comment triggering the PipelineRun when using a [GitOps command]({{< relref "/docs/guide/running.md#gitops-command-on-pull-or-merge-request" >}}) (like `/test`, `/retest`) | `{{trigger_comment}}`               | /merge-pr branch                                                                                                                                              |