docs(readme): Add usage section

README.md

@@ -84,3 +84,23 @@ brew install gabe565/tap/cli-of-life
 
 Download and run the [latest release binary](https://github.com/gabe565/cli-of-life/releases/latest) for your system and architecture.
 </details>
+
+## Usage
+Run `cli-of-life` in a terminal to play.
+
+By default, the grid will be empty, but rle/plaintext files can be loaded with `cli-of-life --file FILE.rle`
+
+See [usage docs](docs/cli-of-life.md) for cli flag documentation.
+
+### Keybinds
+
+| Key     | Description                        |
+|---------|------------------------------------|
+| Mouse   | Place cells                        |
+| `Space` | Play/pause                         |
+| `T`     | Tick                               |
+| `M`     | Toggle between placing and erasing |
+| `W`     | Toggle wrapping                    |
+| `<`/`>` | Change playback speed              |
+| `R`     | Reset                              |
+| `Q`     | Quit                               |