[FIX] Specify Node version at v11, as Node 12+ isn't working

.nvmrc

@@ -0,0 +1 @@
+v11.15.0

CONTRIBUTING.md

@@ -1,31 +1,34 @@
 # Contribute to Schematik Forms
 
-If you decide to fix an issue, please be sure to check the comment thread in case somebody is already working on a fix. 
-If nobody is working on it at the moment, please leave a comment stating that you intend to work on it so other 
+If you decide to fix an issue, please be sure to check the comment thread in case somebody is already working on a fix.
+If nobody is working on it at the moment, please leave a comment stating that you intend to work on it so other
 people don’t accidentally duplicate your effort.
 
-If somebody claims an issue but doesn’t follow up for more than two weeks, it’s fine to take over it but you should 
+If somebody claims an issue but doesn’t follow up for more than two weeks, it’s fine to take over it but you should
 still leave a comment.
 
 ## Getting started
 
 **Prerequisites**
 
-- You have Node installed at v11+ and yarn installed at v1+
-- You understand git and github
+-   You understand git and github
+-   You have `yarn` installed at v1+
+-   You have Node installed at `^11.15.0` per the `.nvmrc`
+    -   You can run `nvm use` to automatically set the correct version according to the project's `.nvmrc` file, if you're using [nvm](https://github.com/nvm-sh/nvm)
+    -   Note this project is currently not compatible with Node 12+ ([GitHub issue](https://github.com/DeloitteDigitalAPAC/schematik-forms/issues/4))
 
 ## Development Workflow
 
-After cloning Schematik Forms, run `yarn install` to install the dependencies. Then the following commands will 
+After cloning Schematik Forms, run `yarn install` to install the dependencies. Then the following commands will
 become available.
 
-- `yarn start` starts a dev server with the cypress fixtures.
-- `yarn lint` checks code style.
-- `yarn test` runs the test suite.
-- `yarn test:unit` runs the unit tests with jest.
-- `yarn test:cypress` runs the cypress tests.
-- `yarn cypress:open` Starts cypress in interactive mode.
-- `yarn docs` Creates the table of contents for the readme file
+-   `yarn start` starts a dev server with the cypress fixtures.
+-   `yarn lint` checks code style.
+-   `yarn test` runs the test suite.
+-   `yarn test:unit` runs the unit tests with jest.
+-   `yarn test:cypress` runs the cypress tests.
+-   `yarn cypress:open` Starts cypress in interactive mode.
+-   `yarn docs` Creates the table of contents for the readme file
 
 ### Building the library
 
@@ -37,6 +40,6 @@ The core maintainers monitor pull request's whom will perform the reviews.
 
 **Before submitting a pull request** please ensure the following is done:
 
-- Fork the repository and create your branch from `master`.
-- If you've fixed a bug or added a feature, add tests.
-- Ensure the tests pass (`yarn test`).
+-   Fork the repository and create your branch from `master`.
+-   If you've fixed a bug or added a feature, add tests.
+-   Ensure the tests pass (`yarn test`).

package.json

@@ -5,6 +5,9 @@
   "main": "./lib/index.js",
   "author": "Deloitte Digital Australia (http://deloittedigital.com.au)",
   "license": "BSD-3-Clause",
+  "engines": {
+    "node": "^11.15.0"
+  },
   "scripts": {
     "clean": "rimraf lib && rimraf dist",
     "start": "cross-env NODE_ENV=development webpack-dev-server --open",