Update docs for controlling modules (#13147)

* update docs for controlling modules

* text update

* clarify

* typo

* add missing word

doc/Developing/os/Settings.md

@@ -99,6 +99,10 @@ per-device in the webui and per os or globally in config.php. Usually,
 a poller module will not work if it's corresponding discovery module
 is not enabled.
 
+You should avoid setting these to false in the OS definitions unless it has a
+significant negative impact on polling.  Setting modules in the definition
+reduces user control of modules.
+
 ```yaml
 poller_modules:
     bgp-peers: true

doc/Support/Configuration.md

@@ -504,13 +504,28 @@ $config['allow_duplicate_sysName'] = false;
 
 ## Global poller and discovery modules
 
-Generally, it is a better to set these [per
+Enable or disable discovery or poller modules.
-OS](../Developing/os/Settings.md#poller-and-discovery-modules) or
-device.
 
-```php
+This setting has an order of precedence Device > OS > Global.
-$config['discovery_modules']['arp-table'] = true;
+So if the module is set at a more specific level, it will override the
-$config['poller_modules']['bgp-peers']    = false;
+less specific settings.
+
+Global:
+
+```bash
+lnms config:set discovery_modules.arp-table false
+
+lnms config:set discovery_modules.entity-state true
+lnms config:set poller_modules.entity-state true
+```
+
+Per OS:
+
+```bash
+lnms config:set os.ios.discovery_modules.arp-table false
+
+lnms config:set os.ios.discovery_modules.entity-state true
+lnms config:set os.ios.poller_modules.entity-state true
 ```
 
 ## SNMP Settings