Updated project documentation to conform to Rubysmith template

Necessary to match consistency used by the
[Rubysmith](https://www.alchemists.io/projects/rubysmith) when
building/maintaining projects.

README.adoc

@@ -51,8 +51,6 @@ image::https://www.alchemists.io/images/screencasts/mac_os/cover.svg[Screencast,
 
 == Setup
 
-=== Production
-
 To install, run:
 
 [source,bash]
@@ -62,16 +60,6 @@ cd mac_os
 git checkout 9.0.0
 ----
 
-=== Development
-
-To contribute, run:
-
-[source,bash]
-----
-git clone https://github.com/bkuhlmann/mac_os.git
-cd mac_os
-----
-
 == Usage
 
 Run the following:
@@ -221,6 +209,16 @@ link:https://www.alchemists.io/projects/mac_os-config[macOS Config] project for
   your system, the version might differ, so look for a `*.pkg` in the
   `/Library/Developer/CommandLineTools/Packages` folder.
 
+== Development
+
+To contribute, run:
+
+[source,bash]
+----
+git clone https://github.com/bkuhlmann/mac_os.git
+cd mac_os
+----
+
 == Versioning
 
 Read link:https://semver.org[Semantic Versioning] for details. Briefly, it means: