Write README.md for general use documentation

Getting Started With the Sonador Command Line Tool Documnetation. After writing the README, transfer the context into a blog posts that describes the CLI in full.

1. First describe the way the CLI is organized and how options are provided (Global -> Group -> Command arguments/options.). The operations get more explicit as you move toward what you want to do.

There are global options, which you can see with:

python sonador-cli.py --help

and there are command options for things like pacs, which you can view with:

python sonador-cli.py pacs --help

For common options, it is possible to pass the values through CLI arguments. (Show an example of providing the arguments via env and an option via explicit CLI option/arg.)

2. Describe the three levels of the API:

• Patient

• Study

• Series

3. Provide example commands:

• - Review the list of imaging servers
• - Upload images to a server, show how the use of the folder argument allows for you to resume a failed upload and describe why that is useful for large datasets
• - Query images
• - Download images to a local folder
• - Query and modify images
• - Remove image series, study, patient
• - Query/remove image series, study, patient