chore(requirements): bit of polish

Author: slack

src/installing-workflow/system-requirements.md

@@ -1,34 +1,45 @@
-# Resource Requirements
+# Requirements
 
-When deploying Deis, it's important to provision machines with adequate resources. Deis is a highly-available distributed system, which means that Deis components and your deployed applications will move around the cluster onto healthy hosts as hosts leave the cluster for various reasons (failures, reboots, autoscalers, etc.). Because of this, you should have ample spare resources on any machine in your cluster to withstand the additional load of running services for failed machines.
+If you are planning to run Deis Workflow on your own Kubernetes cluster there are a few requirements that you should be
+aware of when creating your environment.
 
-## Resources
+## Resource Requirements
 
-Deis components consume approximately 2 - 2.5GB of memory across the cluster, and approximately 30GB of hard disk space. Because each machine should be able to absorb additional load should a machine fail, each machine must have:
+When deploying Deis Workflow, it's important to provision machines with adequate resources. Deis is a highly-available
+distributed system, which means that Deis components and your deployed applications will move around the cluster onto
+healthy hosts as hosts leave the cluster for various reasons (failures, reboots, autoscalers, etc.). Because of this,
+you should have ample spare resources on any machine in your cluster to withstand the additional load of running
+services for failed machines.
+
+Deis Workflow components consume approximately 2 - 2.5GB of memory across the cluster, and approximately 30GB of hard
+disk space. Because each machine should be able to absorb additional load should a machine fail, each machine must
+have:
 
 * At least 4GB of RAM (more is better)
 * At least 40GB of hard disk space
 
-Note that these estimates are for Deis and Kubernetes only, and there should be ample room for deployed applications.
-
-Running smaller machines will likely result in increased system load and has been known to result in component failures and other problems.
-
+Note that these estimates are for Deis Workflow and Kubernetes only. Be sure to leave enough spare capacity for your
+application footprint as well.
 
-# Kubernetes Requirements
+Running smaller machines will likely result in increased system load and has been known to result in component failures and instability.
 
-## Versions
+## Kubernetes Versions
 
-Deis workflow has been tested with the Kubernetes v1.2 release line. It is incompatible with Kubernetes v1.1 and lower.
-
-# Docker Requirements
+Deis Workflow has been tested with the **Kubernetes v1.2** release line. It is incompatible with Kubernetes v1.1 and earlier.
 
 ## Docker Insecure Registry
 
-The on-cluster, Deis-managed Docker registry is not deployed with TLS by default. As such, all Kubernetes worker nodes must have their Docker daemons configured to use an insecure registry. The subnet should encompass any private networks used by your worker nodes, including any overlay networks. Depending on your Kubernetes and Docker configuration, setting `EXTRA_DOCKER_OPTS="--insecure-registry=10.0.0.0/8"` may be sufficient.
+The on-cluster Docker registry is not deployed with TLS enabled. As such, all Kubernetes worker nodes must have their
+Docker daemons configured to use an **insecure registry**. The configured subnet should encompass any private networks
+used by your worker nodes, including overlay networks.
+
+Depending on your Kubernetes and Docker configuration, setting `EXTRA_DOCKER_OPTS="--insecure-registry=10.0.0.0/8"` may
+be sufficient.
 
 ## SELinux + OverlayFS
 
-If you are using Docker with OverlayFS you must disable SELinux by adding `--selinux-enabled=false` to `EXTRA_DOCKER_OPTS`. For more background information see:
+If you are using Docker with OverlayFS you must disable SELinux by adding `--selinux-enabled=false` to
+`EXTRA_DOCKER_OPTS`. For more background information see:
 
 * [https://github.com/docker/docker/issues/7952](https://github.com/docker/docker/issues/7952)
 * [https://github.com/deis/postgres/issues/63](https://github.com/deis/postgres/issues/63)