Added EthereumJS footer with organization docs linking

Author: holgerd77

README.md

@@ -50,3 +50,9 @@ Run
 
 The results are at
 `coverage/lcov-report/index.html`
+
+# EthereumJS
+
+See our organizational [documentation](https://ethereumjs.readthedocs.io) for an introduction to `EthereumJS` as well as information on current standards and best practices.
+
+If you want to join for work or do improvements on the libraries have a look at our [contribution guidelines](https://ethereumjs.readthedocs.io/en/latest/contributing.html).