Add arguments (args)

**Is your feature request related to a problem? Please describe.**
Current vscode built in debugger accepts a launch.json file in the workspace where additional arguments can be added.

**Describe the solution you'd like**
I'd like similar functionality, or a pointer to how to do it (looked through documentation - didn't see anything).

Also useful would be the ability to request args if none are found - so user can enter them interactively.

E.g. launch.json

{
"version": "0.2.0",
"configurations": [

{
"name": "Python: Current File",
"type": "python",
"request": "launch",
"program": "${file}",
"console": "integratedTerminal",
"args": ["arg1", "arg2", "argx"]
}
]
}

This feature seems so obvious I am convinced I am missing something simple...

Start by reviewing how the extension launches the current file and how VS Code launch.json represents an args array. Compare the requested configured arguments with the alternative of prompting when none are supplied. Done means users can pass arguments to the debugger-run program, with the intended interactive behavior clarified and covered by the project's relevant checks.

Written by the indexing model from the issue text.