empathy for those new to typescript projects

CONTRIBUTING.md

@@ -0,0 +1,18 @@
+## bootstrapping
+
+This a [JavaScript](https://help.github.com/en/articles/about-actions#types-of-actions)  action but uses [TypeScript](https://www.typescriptlang.org/docs/home.html) to generate that JavaScript.
+
+You can bootstrap your envrinment with a modern version of npm and by running `npm i` at the root of this repo.
+
+## testing
+
+Tests can be found under under `__tests__` directory and are runnable with the `npm t` command
+
+## source code
+
+Source code can be found under the `src` directory. Running `npm run build` will generate the JavaScript that will run within GitHub workflows.
+
+## formatting
+
+A minimal attempt at keeping a consistent code style is can be applied by running `npm run fmt`
+