fix wrong spells in coredns-007.md
@@ -30,7 +30,7 @@ Back to the release.
* gRPC and TLS are made first class citizens. See [the zone
specification](https://github.com/coredns/coredns/blob/master/README.md#zone-specification) on how
to use it. TL;DR using `grpc://` makes the server talk gRPC. The `tls` directive is used to
- specify TLS certifcates.
+ specify TLS certificates.
* Zipkin tracing can be enabled for all plugin.
# Plugins
