We originally didn't pass build and deploy commands for build and deploy commands parsed out of Markdown files through a shell was because Go's exec.Cmd interface doesn't automatically do it for us. But just recently found out that we can do something like this:

exec.Command("bash", "-c", "echo hello world")

And we could revise the code tag to include the shell we want to run the commands with instead: {sst-run-bash} instead of {sst-run-bash}. This way, we wouldn't have to expand environment variables ourselves either.