Hello World example

[Vertexwahn]

Would it be possible to add a minimal "Hello World" example in the documentation?

I tried it here, but did not get it working:
https://stackoverflow.com/questions/74709415/erlang-hello-world-using-bazel-as-a-build-system

[pjk25]

A response was posted in stackoverflow: https://stackoverflow.com/a/75007131/20928572

Something similar was raised in #32, however it's slightly different, which was part of my hesitation in assuming a singular expecattion for what bazel run //:erlang_app would actually mean.