docs: features/dns-cache: clean up

docs/features/dns-cache.rst

-DNS-Caching
+DNS caching
 ===========
+
 User experience may be greatly improved when dns is accelerated. Also, it
 seems like a good idea to keep the number of packages being exchanged
 between node and gateway as small as possible. In order to do this, a
-dns-cache may be used on a node. The dnsmasq instance listening on port
+DNS cache may be used on a node. The dnsmasq instance listening on port
 53 on the node will be reconfigured to answer requests, use a list of
 upstream servers and a specific cache size if the options listed below are
 added to site.conf. Upstream servers are the DNS servers which are normally
@@ -12,14 +13,14 @@ used by the nodes to resolve hostnames (e.g. gateways/supernodes).
 There are the following settings:
     servers
     cacheentries
-    
-If both options are set the node will cache as much DNS records as set with 
-'cacheentries' in RAM. The 'servers' list will be used to resolve the received 
-DNS-queries if the request cannot be answered from cache.
-If these settings do not exist, the cache is not intialized and RAM-usage will not increase.
-
-When next_node.name is set, an A-record and an AAAA-record for the 
-next-node-IP are placed in the dnsmasq configuration. This means that the content 
+
+If both options are set the node will cache as much DNS records as set with
+'cacheentries' in RAM. The 'servers' list will be used to resolve the received
+DNS queries if the request cannot be answered from cache.
+If these settings do not exist, the cache is not intialized and RAM usage will not increase.
+
+When next_node.name is set, an A record and an AAAA record for the
+next-node IP address are placed in the dnsmasq configuration. This means that the content
 of next_node.name may be resolved even without upstream connectivity.
 
 ::
@@ -28,7 +29,7 @@ of next_node.name may be resolved even without upstream connectivity.
     cacheentries = 5000,
     servers = { '2001:db8::1', },
   },
-  
+
   next_node = {
     name = 'nextnode',
     ip6 = '2001:db8:8::1',