Support for processing individual files/streams #127
Description
Want to be able to do something like this especially in cloudflare workers.
// stream is result of fs.open or similar
markdowndb.processMarkdown(stream) => the result of parsing a single file
We want this so that you can use markdowndb functions to process single rather than have to run on a whole directory.
That means we can process individual markdown files in e.g. cloudflare workers.