Added release notes for 8.4

Signed-off-by: Rinku Kothiya <rkothiya@redhat.com>

docs/release-notes/8.4.md

@@ -0,0 +1,30 @@
+# Release notes for Gluster 8.4
+
+This is a bugfix release. The release notes for [8.0](8.0.md), [8.1](8.1.md), [8.2](8.2.md) and [8.3](8.3.md)
+contain a listing of all the new features that were added
+and bugs fixed in the GlusterFS 8 stable release.
+
+**NOTE:** 
+- Next minor release tentative date: Week of 20th Apr, 2021
+- Users are highly encouraged to upgrade to newer releases of GlusterFS.
+
+## Highlights of Release
+
+- Healing data in 1MB chunks instead of 128KB for improving healing performance [#2067](https://github.com/gluster/glusterfs/issues/2067)
+
+## Builds are available at 
+
+[https://download.gluster.org/pub/gluster/glusterfs/8/8.4/](https://download.gluster.org/pub/gluster/glusterfs/8/8.4/)
+
+## Issues addressed in this release
+
+Please find the list of issues added to this release below.
+
+- [#2154](https://github.com/gluster/glusterfs/issues/2154) "Operation not supported" doing a chmod on a symlink
+- [#2107](https://github.com/gluster/glusterfs/issues/2107) mount crashes when setfattr -n distribute.fix.layout -v "yes"...
+- [#1991](https://github.com/gluster/glusterfs/issues/1991) mdcache: bug causes getxattr() to report ENODATA when fetchin...
+- [#1925](https://github.com/gluster/glusterfs/issues/1925) dht_pt_getxattr does not seem to handle virtual xattrs.
+- [#1539](https://github.com/gluster/glusterfs/issues/1539) fuse mount crashes on graph-switch when reader-thread-count i...
+- [#1529](https://github.com/gluster/glusterfs/issues/1529) Fix regression in on demand migration feature
+- [#1406](https://github.com/gluster/glusterfs/issues/1406) shared storage volume fails to mount in ipv6 environment
+

docs/release-notes/index.md

@@ -7,6 +7,7 @@ Release Notes
 
 ### GlusterFS 8 release notes
 
+- [8.4](./8.4.md)
 - [8.3](./8.3.md)
 - [8.2](./8.2.md)
 - [8.1](./8.1.md)

mkdocs.yml

@@ -118,6 +118,7 @@ nav:
   - RELEASE 9.x:
     - 9.0: release-notes/9.0.md
   - RELEASE 8.x:
+    - 8.4: release-notes/8.4.md
     - 8.3: release-notes/8.3.md
     - 8.2: release-notes/8.2.md
     - 8.1: release-notes/8.1.md