Null directory handlers

[github-actions[bot]]

The distributed version of this will likely contain no directoies for source,

staging, and refined data.

Add handlers to check whether such files and directories exist, and create

them if not.

https://github.com/danmassarano/chatbot/blob/6e0331fc71c5ec2190f74f31c7b643e76521d0dd/issues.md#L1

<!-- TODO: Null directory handlers
    The distributed version of this will likely contain no directoies for source,
    staging, and refined data.
    Add handlers to check whether such files and directories exist, and create
    them if not.
    labels: bug
    assignees: danmassarano
-->