follow up for #4777 (#4778)

* DAG docs - fix broken links and add tags to docs

* change tests

* remove empty line

* fix typo

* fix second test template

* add if case for private-bigquery-etl

bigquery_etl/query_scheduling/templates/airflow_dag.j2

@@ -21,7 +21,7 @@ from utils.callbacks import retry_tasks_callback
 docs = """
 ### {{ name }}
 
-Built from {{ repo }} repo, [`dags/{{ name }}.py`](https://github.com/mozilla/{{ repo }}/blob/generated-sql/dags/{{ name }}.py)
+Built from {{ repo }} repo, [`dags/{{ name }}.py`](https://github.com/mozilla/{{ repo }}/blob/{% if repo == "private-bigquery-etl" %}private-{% endif %}generated-sql/dags/{{ name }}.py)
 
 {% if description != "" -%}
 #### Description

bigquery_etl/query_scheduling/templates/public_data_json_airflow_dag.j2

@@ -11,7 +11,7 @@ from utils.gcp import gke_command
 docs = """
 ### {{ name }}
 
-Built from bigquery-etl repo, [`dags/{{ name }}.py`](https://github.com/mozilla/bigquery-etl/blob/generated-sql/dags/{{ name }}.py)
+Built from bigquery-etl repo, [`dags/{{ name }}.py`](https://github.com/mozilla/bigquery-etl/blob/{% if repo == "private-bigquery-etl" %}private-{% endif %}generated-sql/dags/{{ name }}.py)
 
 {% if description != "" -%}
 #### Description