Update README.md

Grammatical fixes.

middleware/metrics/README.md

@@ -21,12 +21,12 @@ Extra labels used are:
 
 * `proto` which holds the transport of the response ("udp" or "tcp")
 * The address family (`family`) of the transport (1 = IP (IP version 4), 2 = IP6 (IP version 6)).
-* `type` which old the query type, it holds the most common ones (A, AAAA, MX, SOA, CNAME, PTR, TXT,
+* `type` which holds the query type. It holds most common types (A, AAAA, MX, SOA, CNAME, PTR, TXT,
   NS, SRV, DS, DNSKEY, RRSIG, NSEC, NSEC3, IXFR, AXFR and ANY) and "other" which lumps together all
   other types.
 * The `response_rcode_count_total` has an extra label `rcode` which holds the rcode of the response.
 
-If monitoring is enabled queries that do not enter the middleware chain are exported under the fake
+If monitoring is enabled, queries that do not enter the middleware chain are exported under the fake
 domain "dropped" (without a closing dot).
 
 Restarting CoreDNS will stop the monitoring. This is a bug. Also [this upstream
@@ -40,7 +40,7 @@ prometheus
 
 For each zone that you want to see metrics for.
 
-It optionally takes an address where the metrics are exported, the default
+It optionally takes an address to which the metrics are exported; the default
 is `localhost:9153`. The metrics path is fixed to `/metrics`.
 
 ## Examples