Merge pull request #1610 from ekohl/improve-readme

Document how to select a version as its own chapter

Author: bastelfreak

README.md

@@ -74,14 +74,50 @@ If you get an error message from these commands, your permission settings restri
 
 For more details about server configuration parameters, consult the [PostgreSQL Runtime Configuration documentation](http://www.postgresql.org/docs/current/static/runtime-config.html).
 
+#### Selecting a version
+
+The version is intended to be supplied via `postgresql::globals`.
+By default the module tries to derive the version based on the OS facts, but can be overridden.
+This is typically used with the official postgresql.org packages:
+
+```puppet
+class { 'postgresql::globals':
+  manage_package_repo => true,
+  version             => '16',
+}
+
+include postgresql::server
+```
+
+On EL 8 & 9 you can also use DNF modules:
+
+```puppet
+class { 'postgresql::globals':
+  manage_dnf_module => true,
+  version           => '16',
+}
+
+include postgresql::server
+```
+
+If you manage the repositories yourself, overriding the version is sufficient.
+
+```puppet
+class { 'postgresql::globals':
+  version => '16',
+}
+
+include postgresql::server
+```
+
 ### Configure an instance
 
 This module supports managing multiple instances (the default instance is referred to as 'main' and managed via including the server.pp class)
 
-**NOTE:** This feature is currently tested on Centos 8 Streams/RHEL8 with DNF Modules enabled. Different Linux plattforms and/or the Postgresql.org
-packages distribute different Systemd service files or use  wrapper scripts with Systemd to start Postgres. Additional adjustmentments are needed to get this working on these plattforms.
+**NOTE:** This feature is currently tested on CentOS 8 Streams/RHEL8 with DNF Modules enabled. Different Linux platforms and/or the postgresql.org
+packages distribute different systemd service files or use wrapper scripts with systemd to start PostgreSQL. Additional adjustmentments are needed to get this working on these platforms.
 
-#### Working Plattforms
+#### Working Platforms
 
 * Centos 8 Streams
 * RHEL 8
@@ -341,18 +377,6 @@ class { 'postgresql::server':
 }
 ```
 
-To use a specific version of the PostgreSQL package:
-
-```puppet
-class { 'postgresql::globals':
-  manage_package_repo => true,
-  version             => '9.2',
-}
-
-class { 'postgresql::server':
-}
-```
-
 ### Manage remote users, roles, and permissions
 
 Remote SQL objects are managed using the same Puppet resources as local SQL objects, along with a `$connect_settings` hash. This provides control over how Puppet connects to the remote Postgres instances and which version is used for generating SQL commands.