Add nvmrc (#2)

* Add nvmrc

* Add readme and nvm.sh script

* Add note for windows users

README.md

@@ -0,0 +1,44 @@
+## Set up the environment
+
+Install node version manager and required version of node js
+```
+$ chmod u+x ./bin/nvm.sh && ./bin/nvm.sh
+$ nvm install
+```
+
+> For windows use [nvm for windows](https://github.com/coreybutler/nvm-windows)
+
+Install Yarn package manager
+```
+$ brew install yarn --without-node
+```
+
+> Use `--without-node` flag  because nvm version of Node is used
+
+Or download it directly from the [website](https://yarnpkg.com/en/docs/install)
+
+## Install npm packages
+
+```
+$ yarn install --frozen-lockfile
+```
+
+## Available scripts
+
+### Start the server
+
+```
+$ yarn start
+```
+
+### Run ESLint with `--fix` option
+
+```
+$ yarn lint
+```
+
+### Run tests
+
+```
+$ yarn test
+```