Minor doc wording fixups (#581)

website/content/docs/installing/high-availability.mdx

@@ -15,14 +15,18 @@ Installing Boundary as a high availability service requires certain infrastructu
 The following ports should be available:
 
 - Clients must have access to the Controller's port (default 9200)
-- Clients must have access to the Worker's port (defaults 9202)
+- Clients must have access to the Worker's port (default 9202)
 - Workers must have access to the Controller's port (default 9201)
-- Workers must have a route and port access to the targets which they service
+- Workers must have a route and port access to the hosts defined within the system, in order to provide connectivity
 
 ## Architecture
 
-The general architecture for the server infrastructure requires 3 controllers and 3 workers. The documentation here uses virtual machines running on Amazon EC2 as the example environment, but this use
-case can be extrapolated to almost any cloud platform to suit operator needs:
+The general architecture for the server infrastructure requires 3 controllers
+and 3 workers. Note that it is possible to a controller and worker within the
+same process, but the guide here assumes separate deployments. The documentation
+here uses virtual machines running on Amazon EC2 as the example environment, but
+this use case can be extrapolated to almost any cloud platform to suit operator
+needs:
 
 ![](/img/production.png)
 

website/content/docs/installing/index.mdx

@@ -8,4 +8,4 @@ description: |-
 
 # Overview
 
-This section covers installing Boundary for different modes of operation, across different environments.
+This section covers installing Boundary for different modes of operation and across different environments.

website/content/docs/installing/postgres.mdx

@@ -12,8 +12,8 @@ This section covers Postgres-specific installation requirements.
 
 ## Version
 
-Boundary prefers Postgres 11x or greater.
+Boundary has only been tested on Postgres 11 or greater.
 
 ## Network
 
-In non-HA configurations, Boundary servers must be able to reach Postgres. If you're running in [high availability](/docs/installing/high-availability), then the controllers, and not workers, need access to the Postgres server infrastructure.
+Boundary controllers must be able to reach Postgres. In non-HA configurations, this means Boundary servers; if you're running in [high availability](/docs/installing/high-availability), then the controllers need access to the Postgres server infrastructure. Worker nodes never need access to the database.

website/content/docs/installing/systemd.mdx

@@ -12,7 +12,7 @@ This section covers how to install Boundary under the [Systemd]() init system on
 
 ## Filesystem Configuration 
 
-`TYPE` below can be either `worker` or `controller`.
+`TYPE` below can be either `worker` or `controller` if you want to run them independently, e.g. for high availability. If you want to run combined nodes, modify as desired.
 
 1. `/etc/boundary-${TYPE}.hcl`: Configuration file for the boundary service
    See above example configurations.