Set Sublime Text project file to open split screen with specific project file on one side and REPL on other side?

Question

I work on R and Python projects in Sublime Text. I have a .sublime-project file for each project, which I currently use only to specify the folders that I want in the project. For example, myproject.sublime-project might contain the following:

{
    "folders":
    [
        {
            "path": ".",
        },
        {
            "path": "path/to/myproject"
        },
    ],
}

How can I modify this .sublime-project file, so that when I open the file, sublime opens in split screen, where a specific file, say "path/to/myproject/main.r" opens on the left, and a SublimeREPL: R window opens on the right?

I have the packages Origami and SublimeREPL installed.

I've tried googling, but haven't found any good tutorials for setting this up.