Document how to use in github actions

Users might get the following error in CI:
```
💀 Engine error: No such process 💀

The specified process cannot be traced. This could be because the tracer
has insufficient privileges (the required capability is CAP_SYS_PTRACE).
Unprivileged processes cannot trace processes that they cannot send signals
to or those running set-user-ID/set-group-ID programs, for security reasons.
Alternatively, the process may already be being traced.

If your uid matches the uid of the target process you want to analyze, you
can do one of the following to get 'ptrace' scope permissions:

* If you are running inside a Docker container, you need to make sure you
start the container using the '--cap-add=SYS_PTRACE' or '--privileged'
command line arguments. Notice that this may not be enough if you are not
running as 'root' inside the Docker container as you may need to disable
hardening (see next points).

* Try running again with elevated permissions by running 'sudo -E !!'.

* You can disable kernel hardening for the current session temporarily (until
a reboot happens) by running 'echo 0 | sudo tee /proc/sys/kernel/yama/ptrace_scope'.
```

Rather than waiting for them to get the error to notice it, document that when running in github actions they should have a step that runs `echo 0 | sudo tee /proc/sys/kernel/yama/ptrace_scope`.

We can add this in a section of the README file.