revert removal of contributor guide

Author: elichad

README.md

@@ -7,8 +7,8 @@ This lesson is intended to teach users how to use [RO-Crate](https://www.researc
 We welcome all contributions to improve the lesson! Maintainers will do their best to help you if you have any
 questions, concerns, or experience any difficulties along the way.
 
-Have a look at
-the [more detailed guidelines][lesson-example] to learn about proper formatting, ways to render the lesson locally, and even
+We'd like to ask you to familiarize yourself with our [Contribution Guide](CONTRIBUTING.md) and have a look at
+the [more detailed guidelines][lesson-example] on about proper formatting, ways to render the lesson locally, and even
 how to write new episodes.
 
 Please see the current list of [issues][https://github.com/ResearchObject/packaging_data_with_ro-crate/issues] for ideas for contributing to this