Update README

README.md

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 # makey-midi [![Build](https://github.com/Basicprogrammer10/makey-midi/actions/workflows/rust.yml/badge.svg)](https://github.com/Basicprogrammer10/makey-midi/actions/workflows/rust.yml)
 
 Lets you use a [Makey Makey](https://makeymakey.com) to send midi commands!
-When run, this program will load the config file and create a virtual midi out port named 'makey-midi'.
-Pressing the keys defined in the config file will then send their respective note values.
+When run, this program will load the config file and either create a virtual midi output port or connect to another midi device.
+Pressing the keyboard keys defined in the config file will then send their respective note values.
+
+You may want to consider [remapping](https://makeymakey.com/pages/remap) your Makey Makey so you can make use of the click button and so any arrow key inputs don't mess with any synth you have open.
+
+## Usage
+
+After installing, there are two main ways to run the application.
+To connect to an existing midi device or create a new virtual output port.
+When creating an output port, no further configuration is needed and the device name will be 'makey-midi' (`makey-midi create`).
+When connecting to an existing port, you can specify the name of the port or leave it blank to automatically pick one (`makey-midi connect [name]`).
+
+The config parameter allows you to specify a path of the [config file](#config) that contains the key map.
+Omitting this will default to `config.toml` in the current directory.
+The debug flag will log what keys are pressed to the console (Ex: `Key pressed: UpArrow`).
+Below is the output of running `makey-midi --help`.
+
+```plain
+Usage: makey-midi [OPTIONS] <COMMAND>
+
+Commands:
+  connect  Connects to a MIDI device to send events to
+  create   Creates a new virtual MIDI output device. Only works on Linux.
+  list     Lists all available MIDI devices. For use with the `connect` subcommand
+  help     Print this message or the help of the given subcommand(s)
+
+Options:
+  -c, --config <CONFIG>  The location of the config file. Defaults to `config.toml` in the current directory
+  -d, --debug            Logs each key event to stdout
+  -h, --help             Print help
+```
+
+Here is an example command.
+This will load the default config file, enable debug output, and connect to the (pretty bad) built-in midi synth in windows.
+
+```shell
+makey-midi --debug connect "Microsoft GS Wavetable Synth"
+```
 
 ## Config
 
 Below is an example `config.toml` file.
 The `channel` defined what channel the midi events are sent on.
 The `keymap` is the main part where you map keyboard keys to midi notes.
-A list of all possible key values is in the dropdown below and a table of midi notes can be found [here](https://www.inspiredacoustics.com/en/MIDI_note_numbers_and_center_frequencies).
+A list of all possible key values is in the dropdown below, and a table of midi notes can be found [here](https://www.inspiredacoustics.com/en/MIDI_note_numbers_and_center_frequencies).
 
 ```toml
 channel = 0