update readme and contributing guide

CONTRIBUTING.md

@@ -59,8 +59,6 @@ The following steps will happen automatically from a GitHub Actions workflow
 after creating the release. In case that fails, the following steps can be performed manually
 
 11. Push the gem from (7) to rubygems.org -- `gem push licensed-x.xx.xx.gem`
-12. Build packages for new tag: `VERSION=x.xx.xx bundle exec rake package`
-13. Upload packages from (12) to release from (10)
 
 ## Resources
 

README.md

@@ -1,8 +1,6 @@
 # Licensed
 
-Licensed caches the licenses of dependencies and checks their status.
-
-Licensed is available as a Ruby gem for Ruby environments, and as a self-contained executable for non-Ruby environments.
+Licensed caches the licenses of dependencies and checks their status, and is available as a Ruby gem.
 
 Licensed is **not** a complete open source license compliance solution. Please understand the important [disclaimer](#disclaimer) below to make appropriate use of Licensed.
 
@@ -12,6 +10,10 @@ Licensed is **not** a complete open source license compliance solution. Please u
 
 Licensed is in active development and currently used at GitHub.  See the [open issues](https://github.com/github/licensed/issues) for a list of potential work.
 
+## Licensed v4 - **Removed support for non-Ruby environments**
+
+Licensed v4 no longer provides a self-contained executable build of licensed.  Please see [the deprecation notice](https://github.com/github/licensed/issues/585) for more context.
+
 ## Licensed v3
 
 Licensed v3 includes a breaking change if both of the following are true:
@@ -59,19 +61,6 @@ And then execute:
 $> bundle
 ```
 
-### As an executable
-
-Download a package from GitHub and extract the executable.  Executable packages are available for each release starting with version 1.2.0.
-
-```bash
-$> curl -sSL https://github.com/github/licensed/releases/download/<version>/licensed-<version>-<os>-x64.tar.gz > licensed.tar.gz
-$> tar -xzf licensed.tar.gz
-$> rm -f licensed.tar.gz
-$> ./licensed list
-```
-
-For system wide usage, install licensed to a location on `$PATH`, e.g. `/usr/local/bin`.
-
 ## Usage
 
 See [getting started](./docs/getting_started.md) for guidance using Licensed as part of your developer workflow.