Add info about posting validation issues to Crowdin to translation docs

doc/development/i18n/merging_translations.md

@@ -23,13 +23,20 @@ translations. Static analysis validates things Crowdin doesn't do. Create
 a new pipeline at [`https://gitlab.com/gitlab-org/gitlab/pipelines/new`](https://gitlab.com/gitlab-org/gitlab/pipelines/new)
 (requires the Developer role) for the `master-i18n` branch.
 
-If there are validation errors, the easiest solution is to disapprove
-the offending string in Crowdin, leaving a comment with what is
-required to fix the errors. There's an
-[issue](https://gitlab.com/gitlab-org/gitlab/-/issues/23256)
-that suggests automating this process. Disapproving excludes the
-invalid translation. The merge request is then updated within a few
-minutes.
+The pipeline job validates translations with the [`PoLinter` class](https://gitlab.com/gitlab-org/gitlab/-/blob/master/lib/gitlab/i18n/po_linter.rb).
+If the linter finds any errors, they appear in the job log.
+For an example of a failed pipeline, see [these error messages](https://gitlab.com/gitlab-org/gitlab/-/jobs/6771832489#L873).
+
+If validation errors occur, you must manually disapprove the offending string
+in Crowdin and leave a comment about how to fix the errors:
+
+1. Sign in to Crowdin with the `gitlab-crowdin-bot` account.
+1. Find the offending string.
+1. Select **Current translation is wrong** to disapprove the translation for the specific target language.
+1. Include the error message from the job log as a comment.
+
+The invalid translation is then excluded, and the merge request is updated.
+Automating this process is proposed in [issue 23256](https://gitlab.com/gitlab-org/gitlab/-/issues/23256).
 
 If the translation fails validation due to angle brackets (`<` or `>`),
 it should be disapproved in Crowdin. Our strings must use [variables](externalization.md#html)