README: minimal changes to say we're a DNS server (#2743)

Small tweaks, tell we're a DNS server.

Signed-off-by: Miek Gieben <miek@miek.nl>

README.md

@@ -7,8 +7,8 @@
 [![Go Report Card](https://goreportcard.com/badge/github.com/coredns/coredns)](https://goreportcard.com/report/coredns/coredns)
 [![CII Best Practices](https://bestpractices.coreinfrastructure.org/projects/1250/badge)](https://bestpractices.coreinfrastructure.org/projects/1250)
 
-CoreDNS (written in Go) chains [plugins](https://coredns.io/plugins). Each plugin performs a DNS
-function.
+CoreDNS is a DNS server/forwarder, written in Go, that chains [plugins](https://coredns.io/plugins).
+Each plugin performs a (DNS) function.
 
 CoreDNS is a [Cloud Native Computing Foundation](https://cncf.io) graduated project.
 
@@ -17,7 +17,8 @@ are able to do what you want with your DNS data by utilizing plugins. If some fu
 provided out of the box you can add it by [writing a plugin](https://coredns.io/explugins).
 
 CoreDNS can listen for DNS requests coming in over UDP/TCP (go'old DNS), TLS ([RFC
-7858](https://tools.ietf.org/html/rfc7858)) and [gRPC](https://grpc.io) (not a standard).
+7858](https://tools.ietf.org/html/rfc7858)), also called DoT, DNS over HTTP/2 - DoH -
+([RFC 8484](https://tools.ietf.org/html/rfc7858)) and [gRPC](https://grpc.io) (not a standard).
 
 Currently CoreDNS is able to:
 
@@ -27,7 +28,7 @@ Currently CoreDNS is able to:
 * Load balancing of responses (*loadbalance*).
 * Allow for zone transfers, i.e., act as a primary server (*file*).
 * Automatically load zone files from disk (*auto*).
-* Caching (*cache*).
+* Caching of DNS responses (*cache*).
 * Use etcd as a backend (replace [SkyDNS](https://github.com/skynetservices/skydns)) (*etcd*).
 * Use k8s (kubernetes) as a backend (*kubernetes*).
 * Serve as a proxy to forward queries to some other (recursive) nameserver (*forward*).