Add documentation for TaskFlowAPI branching and update the tutorial

[matwasilewski]

What do you see as an issue?

When learning Airflow, I could not find documentation for branching in TaskFlowAPI. I finally found @task.branch(task_id="<TASK_ID>") via an example from the github repo - but it seems to be the only place where this feature is mentioned, which makes it very difficult to find.

Solving the problem

I suggest adding "branching in TaskFlowAPI" to the official documentation, and including an example of branching in TaskFlowAPI Tutorial. I would be happy to update the docs.

Anything else

Generally, my feeling is that the TaskFlowAPI is still poorly documented and has a long way to go - so if there were any other elements that should be added to the docs together with information about branching let me know and I am happy to write that docs.

Are you willing to submit PR?

• Yes I am willing to submit a PR!

Code of Conduct

• I agree to follow this project's Code of Conduct

[boring-cyborg]

Thanks for opening your first issue here! Be sure to follow the issue template!

[potiuk]

I assigned you!
Absolutely! Feel free to update the docs! Airflow is created by > 2100 contributors like you - including contributing the docs :). Having contributions for the users in the docs where they find missing information is one of the most valuable contributions from users. As a user who struggled with and finally found answer and tried it, you are uniquely positioned to be one of the best people who could do it well :). The creators of Task Flow have too many assumptions in their heads, many things are "obvious" to them, so their documentation is never perfect for users like you, who just learn.

BTW. You might not realise how easy, it is to contribute the docs. Simply go to the documentation and choose "Suggest a change on this page" button at the bottom right - and it will automatically open a PR in GitHub where you will be able to edit the documentation using GitHub UI. Only if you need some complex case (like embedding examples) you might need to setup the development environment - but for documentation it is very easy using breeze that takes literally minutes to setup. See https://github.com/apache/airflow/blob/main/CONTRIBUTORS_QUICK_START.rst

[dylanzenner]

Can I take this? I work with airflow daily and just recently had the same issue as this person but I also needed to figure out how branching worked with task groups.

[potiuk]

assigned