docs: better README

README.md

@@ -4,6 +4,34 @@
 
 This has been a [PyCamp.es](https://pycamp.es) 2024 project, use with discretion.
 
+## Installation
+
+```sh
+pipx install ficamp
+```
+
+Alternatively:
+
+```sh
+pip install -U --user ficamp
+```
+
+## Usage
+
+```terminal
+$ ficamp --help
+usage: ficamp [-h] [--bank {abn}] filename
+
+Print the first argument from the CLI
+
+positional arguments:
+  filename      The spreadsheet to load
+
+options:
+  -h, --help    show this help message and exit
+  --bank {abn}
+```
+
 ## Contributing
 
 Read [CONTRIBUTING.md](./CONTRIBUTING.md).