docs: clarify that all labels must exist (#11693)

It's unclear if all or any of the labels need to exist. This clarifies that all of the labels must exist.

Signed-off-by: Nicholas Morey <nicholas@morey.tech>

Signed-off-by: Nicholas Morey <nicholas@morey.tech>

docs/operator-manual/applicationset/Generators-Pull-Request.md

@@ -60,7 +60,7 @@ spec:
 * `repo`: Required name of the GitHub repository.
 * `api`: If using GitHub Enterprise, the URL to access it. (Optional)
 * `tokenRef`: A `Secret` name and key containing the GitHub access token to use for requests. If not specified, will make anonymous requests which have a lower rate limit and can only see public repositories. (Optional)
-* `labels`: Labels is used to filter the PRs that you want to target. (Optional)
+* `labels`: Filter the PRs to those containing **all** of the labels listed. (Optional)
 * `appSecretName`: A `Secret` name containing a GitHub App secret in [repo-creds format][repo-creds].
 
 [repo-creds]: ../declarative-setup.md#repository-credentials