Add continuous integration note to runtime environment.

README.md

@@ -27,6 +27,10 @@ For any of the subsequent commands, they can be executed by either running `[the
 
 If you switch between containerized and local runtime, you may need to remove compiled Stan programs because binaries are not interoperable. Run `[./in-docker.sh] cook exec rm-compiled` to do so.
 
+### Continuous integration
+
+To ensure the reproducibility of these materials, the results are also computed as the output of a GitHub Action workflow [![Reproduction Materials](https://github.com/tillahoffmann/gptools-reproduction-material/actions/workflows/main.yaml/badge.svg)](https://github.com/tillahoffmann/gptools-reproduction-material/actions/workflows/main.yaml) with the `FAST=true` flag. Figures can be obtained by selecting a workflow run and downloading the `figures-reports` artifact.
+
 ## Running the experiments
 
 Figures in the manuscript were generated using the containerized runtime, and all runtime estimates below are based on a 2020 Macbook Pro with M1 chip and 16 GB of memory running macOS 13.4 (22F66). Figures are generated by executing Jupyter notebooks stored in markdown format. All figures can be reproduced by running `[./in-docker.sh] cook exec figures` (see below for details).