Add preliminary notes for 1.8.4 (#4535)

* Add preliminary notes for 1.8.4

Draft notes for 1.8.4
Signed-off-by: Miek Gieben <miek@miek.nl>

* Update notes/coredns-1.8.4.md
Co-authored-by: Chris O'Haver <cohaver@infoblox.com>

* Update notes/coredns-1.8.4.md
Co-authored-by: Chris O'Haver <cohaver@infoblox.com>

* Update notes/coredns-1.8.4.md
Co-authored-by: Chris O'Haver <cohaver@infoblox.com>
Co-authored-by: Chris O'Haver <cohaver@infoblox.com>

notes/coredns-1.8.4.md

++++
+title = "CoreDNS-1.8.4 Release"
+description = "CoreDNS-1.8.4 Release Notes."
+tags = ["Release", "1.8.4", "Notes"]
+release = "1.8.4"
+date = 2021-03-24T07:00:00+00:00
+author = "coredns"
++++
+
+The CoreDNS team has released
+[CoreDNS-1.8.4](https://github.com/coredns/coredns/releases/tag/v1.8.4). This release includes a
+bunch of bugfixes and a few enhancements, see below.
+TODO
+
+## Brought to You By
+
+Chris O'Haver,
+Miek Gieben,
+Mohammad Yosefpor,
+Paco Xu,
+Soumya Ghosh Dastidar.
+
+## Noteworthy Changes
+
+* plugin/metrics: remove RR type (https://github.com/coredns/coredns/pull/4534)
+* plugin/health: add logging for local health request (https://github.com/coredns/coredns/pull/4533)
+* plugin/bind: Bind by interface name (https://github.com/coredns/coredns/pull/4522)
+* plugin/bind: Exclude interface or ip address  (https://github.com/coredns/coredns/pull/4543)
+* plugin/forward: Add upstream metadata (https://github.com/coredns/coredns/pull/4521)
+* plugin/minimal: Add minimal-responses plugin (https://github.com/coredns/coredns/pull/4417)
+* plugin/transfer: reply with refused (https://github.com/coredns/coredns/pull/4510)
+* plugin/kubernetes: Exclude unready endpoints from endpointslices (https://github.com/coredns/coredns/pull/4580)
+* plugin/kubernetes: do endpoint/slice check in retry loop (https://github.com/coredns/coredns/pull/4492)