docs: minor grammer/wording fixes

docs/features/multidomain.rst

@@ -188,7 +188,7 @@ domain.conf only variables
       - ``true``, ``false``
       - ``{ 'foo', 'bar' }``
 
-- Because each domain is considered as an own layer 2 network, these
+- Because each domain is considered a separate layer 2 network, these
   values should be different in each domain:
 
   - next_node.ip4

docs/user/site.rst

@@ -68,7 +68,7 @@ ntp_servers
 
     ntp_servers = {'1.ntp.services.ffac','2.ntp.services.ffac'}
 
-  This NTP servers must be reachable via IPv6 from the nodes. If you don't want to set an IPv6 address
+  These NTP servers must be reachable via IPv6 from the nodes. If you don't want to set an IPv6 address
   explicitly, but use a hostname (which is recommended), see also the :ref:`FAQ <faq-dns>`.
 
 opkg \: optional