[AIRFLOW-XXXX] Fix typo from upstream to downstream (#7595)
[AIRFLOW-XXXX] Fix typo from upstream to downstream (#7595)

This is how it used to be:
Each DAG Run will contain a task_1 Task Instance and a task_2 Task instance. Both Task Instances will
have ``execution_date`` equal to the DAG Run's ``execution_date``, and each task_2 will be *upstream* of
(depends on) its task_1.

if task_2 depends on task_1 this means task_2 is set downstream of tastk_1  - wondering if I am missing something here - or misreading it
apache/incubator-airflow,bolkedebruin/airflow,lyft/incubator-airflow,dhuang/incubator-airflow,wooga/airflow,dhuang/incubator-airflow,nathanielvarona/airflow,mistercrunch/airflow,dhuang/incubator-airflow,nathanielvarona/airflow,mistercrunch/airflow,nathanielvarona/airflow,apache/incubator-airflow,cfei18/incubator-airflow,DinoCow/airflow,mistercrunch/airflow,dhuang/incubator-airflow,bolkedebruin/airflow,bolkedebruin/airflow,Acehaidrey/incubator-airflow,apache/airflow,DinoCow/airflow,wooga/airflow,sekikn/incubator-airflow,airbnb/airflow,cfei18/incubator-airflow,sekikn/incubator-airflow,danielvdende/incubator-airflow,wooga/airflow,sekikn/incubator-airflow,airbnb/airflow,sekikn/incubator-airflow,danielvdende/incubator-airflow,nathanielvarona/airflow,cfei18/incubator-airflow,cfei18/incubator-airflow,lyft/incubator-airflow,Acehaidrey/incubator-airflow,bolkedebruin/airflow,cfei18/incubator-airflow,Acehaidrey/incubator-airflow,mrkm4ntr/incubator-airflow,mistercrunch/airflow,danielvdende/incubator-airflow,mrkm4ntr/incubator-airflow,danielvdende/incubator-airflow,mrkm4ntr/incubator-airflow,danielvdende/incubator-airflow,mrkm4ntr/incubator-airflow,airbnb/airflow,apache/airflow,bolkedebruin/airflow,apache/incubator-airflow,apache/airflow,apache/airflow,DinoCow/airflow,apache/airflow,Acehaidrey/incubator-airflow,nathanielvarona/airflow,Acehaidrey/incubator-airflow,nathanielvarona/airflow,Acehaidrey/incubator-airflow,airbnb/airflow,apache/airflow,lyft/incubator-airflow,cfei18/incubator-airflow,danielvdende/incubator-airflow,wooga/airflow,DinoCow/airflow,lyft/incubator-airflow,apache/incubator-airflow