Add a workflow for welcoming first-time contributors

[AnthonyLatsis]

I tested the workflow in my swift fork, albeit without the first-time contributor condition. Once this lands, we can use the contributor experience repo to further test it against pull requests from forks.

[ahoppen]

I don’t think this workflow design will work because GitHub Actions will be disabled for first-time contributors and thus the action will not trigger on the `pull_request_target

[AnthonyLatsis]

I don’t think this workflow design will work because GitHub Actions will be disabled for first-time contributors and thus the action will not trigger on the `pull_request_target

I am reading through this and getting the impression that the limitation applies to workflow runs — regardless of whether they depend on actions. But the note says that pull_request_target is never run in a (unsafe) fork context and, thus, is an exception. I assume the issues event could similarly be triggered by anyone because the workflow would always run in the context of the issue’s repository.

[ahoppen]

I am reading through this and getting the impression that the limitation applies to workflow runs — regardless of whether they depend on actions. But the note says that pull_request_target is never run in a (unsafe) fork context and, thus, is an exception. I assume the issues event could similarly be triggered by anyone because the workflow would always run in the context of the issue’s repository.

I’m sorry. I meant to remove that comment after I realized that you’re using pull_request_target but must have forgotten.

[ahoppen]

Looks good to me but I would like @shahmishal to review this as well because it’s a new workflow.

[AnthonyLatsis]

Sure, I’d like that too! Thanks for reviewing, Alex.

[FranzBusch]

Can we provide a default message for both? Would avoid every repo to define its own custom message. Maybe even going one step further do we want each repo to customise this really? If so how do you expect them to customise this?

[xedin]

The text for the message itself that Contributor Experience Workgroup discussed:

Thank you for the contribution and welcome to our community! Since this is your first contribution to the
<<project>>, we want to make sure that you know about our [Code of Conduct](https://www.swift.org/code-of-conduct/), [Contributing Code](https://www.swift.org/contributing) guide, and other useful resources available on [swift.org](http://swift.org/).
We put emphasis on code quality, so all changes to the project must be [reviewed](https://www.swift.org/contributing/#code-review) before they are committed to the repository. To facilitate that, one or more reviewers have been automatically assigned to this pull request. They will provide feedback, run CI, and help land the changes.

[parispittman]

ship it :)