Add note about git-lfs to README

README.md

@@ -6,7 +6,7 @@ Action is written in Python and requires a number of dependencies and large mach
 
 The easiest way to use it is with the [pixi](https://prefix.dev/docs/pixi/overview) package manager.  Pixi installs everything you need into a local `.pixi` folder (i.e., at the root of the project), without needing to modify your system.
 
-1. Clone this repo using `git clone https://github.com/humphrem/action.git`
+1. Clone this repo using `git clone https://github.com/humphrem/action.git`. NOTE: the repo includes large `.onnx` model files, which will get downloaded if you have [`git-lfs`](https://git-lfs.com/) installed (otherwise we'll get them as part of the setup below).
 2. [Install pixi](https://prefix.dev/docs/pixi/overview#installation)
 3. Start a terminal and navigate to the root of the Action project folder you just cloned, `cd action`
 4. Enter the command `pixi run setup` to download, install, and setup everything you'll need