Added contribution instructions

Author: keul

CONTRIBUTING.md

@@ -0,0 +1,30 @@
+# How to contribute
+
+## Requirements
+
+- node 14.4 - Tested on 14.4 and 14.19. Unluckily there are [dev server issues with more recent versions](https://stackoverflow.com/questions/69692842/error-message-error0308010cdigital-envelope-routinesunsupported).
+- make (recommended)
+
+## Installation
+
+```bash
+make install
+```
+
+This will install both the package and the example application.
+
+## Running
+
+```bash
+make start
+```
+
+This will run a local development server with live-reload capabilities.
+
+## E2E tests
+
+```bash
+e2e_open
+```
+
+Open the Cypress user interfare for running E2E tests interactively.