Document updates: (#2075)

Update the how to release notes in Makefile.release
And some little community tweaks in the README.md
Signed-off-by: Miek Gieben <miek@miek.nl>

Makefile.release

@@ -18,18 +18,19 @@
 # * Send PR to get this merged.
 #
 # * Open an issue for this release
-# * In an issue give the command: /release: master
-# * (to test as release /release: -t master can be used.
+# * In an issue give the command: /release: master VERSION
+#   Where VERSION is the version of the release - the release script double checks this with the
+#   actual CoreDNS version in coremain/version.go
+# * (to test as release /release: -t master VERSION can be used.
 #
-# See github.com/coredns/release for documentation README on what needs to be setup for this to be
+# See https://github.com/coredns/release for documentation README on what needs to be setup for this to be
 # automated (can still be done by hand if needed). Especially what environment variables need to be
 # set!
 #
-# To release we run, where 'release' and 'docker' only locally build assets; these are the same
-# targets that get executed in case of testing.
+# To release we run, these target from the this Makefile:
 # * make release
-# * make github-push
 # * make docker
+# * make github-push
 # * make docker-push
 
 EMPTY:=

README.md

@@ -186,17 +186,17 @@ When no transport protocol is specified the default `dns://` is assumed.
 
 ## Community
 
-We're most active on Slack (and Github):
+We're most active on Github (and Slack):
 
-- Slack: #coredns on <https://slack.cncf.io>
 - Github: <https://github.com/coredns/coredns>
+- Slack: #coredns on <https://slack.cncf.io>
 
 More resources can be found:
 
 - Website: <https://coredns.io>
 - Blog: <https://blog.coredns.io>
 - Twitter: [@corednsio](https://twitter.com/corednsio)
-- Mailing list/group: <coredns-discuss@googlegroups.com>
+- Mailing list/group: <coredns-discuss@googlegroups.com> (not very active)
 
 ## Deployment