Update README with getting started (opensearch-project#549)

Update README with getting started instructions

Signed-off-by: Jonah Kowall <jkowall@kowall.net>

README.md

@@ -6,6 +6,10 @@ OpenSearch is an open source search and analytics engine derived from Elasticsea
 
 We officially began work on the new fork on January 21st, 2021.  Since then, we've been removing non-Apache 2.0 compliant code and doing a full rename of the project.  Feel free to take a look around at what we've been up to, and then head over to look at the [open issues](https://github.com/opensearch-project/OpenSearch/issues).  Or you could jump right in and [start opening issues](https://github.com/opensearch-project/OpenSearch/issues/new/choose) or [contributing](https://github.com/opensearch-project/OpenSearch/blob/main/CONTRIBUTING.md).
 
+## Getting Started
+
+If you would like to install or run this project please see the [Developer Guide](https://github.com/opensearch-project/OpenSearch/blob/main/DEVELOPER_GUIDE.md). There will be binary distributions coming soon which will enable faster installations. 
+
 ## Guiding Principles
 
 Here are the principles we use to guide our development.  From [opensearch.org](http://opensearch.org):