Fix mysql_plugin examples and add section in README

Author: Markus Opolka

README.md

@@ -13,6 +13,7 @@
     * [Specify passwords](#specify-passwords)
     * [Install Percona server on CentOS](#install-percona-server-on-centos)
     * [Install MariaDB on Ubuntu](#install-mariadb-on-ubuntu)
+    * [Install Plugins](#install-plugins)
 4. [Reference - An under-the-hood peek at what the module is doing and how](REFERENCE.md)
 5. [Limitations - OS compatibility, etc.](#limitations)
 6. [Development - Guide for contributing to the module](#development)
@@ -382,6 +383,22 @@ mysql::server::db:
 
 ```
 
+### Install Plugins
+
+Plugins can be installed by using the `mysql_plugin` defined type. See `examples/mysql_plugin.pp` for futher examples.
+
+```puppet
+class { 'mysql::server':
+  root_password => 'password'
+}
+
+mysql_plugin { 'auth_pam':
+  ensure => present,
+  soname => 'auth_pam.so',
+}
+
+```
+
 ### Tasks
 
 The MySQL module has an example task that allows a user to execute arbitary SQL against a database. Please refer to to the [PE documentation](https://puppet.com/docs/pe/2017.3/orchestrator/running_tasks.html) or [Bolt documentation](https://puppet.com/docs/bolt/latest/bolt.html) on how to execute a task.

examples/mysql_plugin.pp

@@ -7,7 +7,7 @@
   default => 'validate_password.so'
 }
 
-mysql::plugin { 'validate_password':
+mysql_plugin { 'validate_password':
   ensure => present,
   soname => $validate_password_soname,
 }
@@ -17,7 +17,7 @@
   default => 'auth_socket.so'
 }
 
-mysql::plugin { 'auth_socket':
+mysql_plugin { 'auth_socket':
   ensure => present,
   soname => $auth_socket_soname,
 }