Update readme

README.md

@@ -14,6 +14,22 @@ Scooter respects both `.gitignore` and `.ignore` files.
 
 You can add capture groups to the search regex and use them in the replacement string: for instance, if you use `(\d) - (\w+)` for the search text and `($2) "$1"` as the replacement, then `9 - foo` would be replaced with `(foo) "9"`.
 
+## Usage
+
+Run
+
+```sh
+scooter
+```
+
+in a terminal to launch Scooter. By default the current directory is used to search and replace in, but you can pass in a directory as the first argument to override this behaviour:
+
+```sh
+scooter ../foo/bar`
+```
+
+You can then enter some text to search with and text to replace matches with, toggle on or off fixed strings, and enter a regex pattern that filenames must match. A more extensive set of keymappings will be shown at the bottom of the window: these vary slightly depending on the screen you're on.
+
 ## Installation
 
 ### Cargo
@@ -34,10 +50,6 @@ cd scooter
 cargo install --path .
 ```
 
-## Usage
-
-Run `scooter` in a terminal to launch Scooter. You can then enter some text to search with and text to replace matches with, toggle on or off fixed strings, and enter a regex pattern that filenames must match. A more extensive set of keymappings will be shown at the bottom of the window: these vary slightly depending on the screen you're on.
-
 ## Contributing
 
 Contributions are very welcome! I'd be especially grateful for any contributions to add scooter to popular package managers. If you'd like to add a new feature, please create an issue first so we can discuss the idea, then create a PR with your changes.