Adding the info on the API key setup

Author: larsvilhuber

README-setup.md

@@ -0,0 +1,27 @@
+# Tutorial
+
+## Setup
+
+- Is usually run on Github Actions
+- Can be run locally, see `run.sh` for plain R, or `render.sh` using Docker
+- If run locally, a `.Renviron` file is needed with the requisite API key.
+
+## API keys
+
+Read the tutorial (natch) and get an API key.
+
+## Setting up the API key for Github
+
+Edit the `.Renviron` file, then set the API key using the `gh` command line tool:
+
+```
+gh secret set -f .Renviron
+```
+
+then check that they were actually set:
+
+```
+gh secret list
+```
+
+