Apply suggestions from code review

Co-authored-by: MatthewCroughan <[email protected]>

Author: doanac

source/reference-manual/security/factory-registration-ref.rst

@@ -21,13 +21,13 @@ Fully detached
 In this scenario devices connect to a reference server instance on
 a private network. This network is isolated from the internet
 (api.foundries.io). Devices get a valid signed client certificate from
-the reference server. Each device will be created in api.foundries.io
+the reference server. Each device will be created via api.foundries.io
 **on-the-fly** the first time they connect.
 
 This scenario is handy for certain security constrained setups. However,
 it does have a couple of potential drawbacks:
 
- * Devices don't show up in the Foundries.io until the first time
+ * Devices don't show up on Foundries.io until the first time
    they connect.
 
  * Devices won't have Foundries.io managed configuration data available
@@ -38,7 +38,7 @@ lmp-device-auto-register configuration
 lmp-device-register must be called with two environment variables
 set to work with the reference server::
 
- DEVICE_API="http://<registration refernce uri>/sign"
+ DEVICE_API="http://<registration reference uri>/sign"
  PRODUCTION=1
 
 A factory can copy `lmp-device-auto-register`_ into their