Updated documentation for clarification and to include the 'flatten' option in glob_to_multiple example

Updated documentation to include the 'flatten' option in glob_to_multiple example (didn't warrant its own use-case example). Added detail about finding more information for the 'expand' API in the glob_to_multiple example.

I updated the example in /docs, but was unsure if I needed to generate the readme, and if so, how.