Added release notes for 5.6 release

Signed-off-by: ShyamsundarR <srangana@redhat.com>

docs/release-notes/5.6.md

@@ -0,0 +1,34 @@
+# Release notes for Gluster 5.6
+
+This is a bugfix release. The release notes for [5.0](5.0.md), [5.1](5.1.md), [5.2](5.2.md), [5.3](5.3.md) and [5.5](5.5.md) contains
+a listing of all the new features that were added and bugs fixed in the
+GlusterFS 5 stable release.
+
+**NOTE:** Next minor release tentative date: Week of 10th June, 2019
+
+**NOTE:** Release 5.4 was never announced as there was a fix which prevented
+rolling upgrades from working correctly. Hence this release notes contains a
+skip from 5.3 till 5.5 in terms of issues addressed and also addresses the
+issue were rolling upgrades were broken.
+
+## Major changes, features and limitations addressed in this release
+
+**None**
+
+## Major issues
+
+Several users had issues around increased network usage after upgrading to 5.x
+release, this issue was tracked against [bug#1673058](https://bugzilla.redhat.com/show_bug.cgi?id=1673058) and is now addressed as
+a part of this minor release.
+
+## Bugs addressed
+
+Bugs addressed since release-5.5 are listed below.
+
+- [#1673058](https://bugzilla.redhat.com/1673058): Network throughput usage increased x5
+- [#1690952](https://bugzilla.redhat.com/1690952): lots of "Matching lock not found for unlock xxx" when using disperse (ec) xlator
+- [#1694562](https://bugzilla.redhat.com/1694562): gfapi: do not block epoll thread for upcall notifications
+- [#1694612](https://bugzilla.redhat.com/1694612): glusterd leaking memory when issued gluster vol status all tasks continuosly
+- [#1695391](https://bugzilla.redhat.com/1695391): GF_LOG_OCCASSIONALLY API doesn't log at first instance
+- [#1695403](https://bugzilla.redhat.com/1695403): rm -rf fails with  "Directory not empty"
+- [#1696147](https://bugzilla.redhat.com/1696147): Multiple shd processes are running on brick_mux environmet

docs/release-notes/index.md

@@ -7,6 +7,7 @@ Release Notes
 
 ### GlusterFS 5 release notes
 
+- [5.6](./5.6.md)
 - [5.5](./5.5.md)
 - [5.3](./5.3.md)
 - [5.2](./5.2.md)

mkdocs.yml

@@ -110,6 +110,7 @@ nav:
 - Release Notes:
   - index: release-notes/index.md
   - 6.0: release-notes/6.0.md
+  - 5.6: release-notes/5.6.md
   - 5.5: release-notes/5.5.md
   - 5.3: release-notes/5.3.md
   - 5.2: release-notes/5.2.md