Document running as Nix flake

Author: mawkler

README.md

@@ -55,19 +55,30 @@ Examples:
 
 You can also run `maconomy get --help`, `maconomy set --help`, etc. to see more info on how to use each command.
 
-## Installation
+## Running/installing
+
+Requires a [configuration](#configuration).
+
+### Option 1: running as a Nix flake
+
+Requires having [Nix](https://github.com/NixOS/nix) installed [with flakes enabled](https://wiki.nixos.org/wiki/Flakes#Setup).
 
 ```sh
-git clone https://github.com/mawkler/maconomy-cli
-cargo install --path maconomy-cli/
+nix run github:mawkler/maconomy-cli --
 ```
 
-[Here's more information](https://doc.rust-lang.org/cargo/getting-started/installation.html) on how to install cargo (Rust's build-tool).
+### Option 2: installing with Cargo
 
-### Dependencies
+Requires:
 
+- [Cargo](https://doc.rust-lang.org/cargo/getting-started/installation.html)
 - [Chromium](https://chromium.woolyss.com/download/) or Google Chrome (used in the current authentication implementation)
 
+```sh
+git clone https://github.com/mawkler/maconomy-cli
+cargo install --path maconomy-cli/
+```
+
 ### Configuration
 
 Configuration is done in the file `~/.config/maconomy-cli/config.toml`. Here's what the config file should look like. All fields except `cookie_path` are required: