Updated Communication in Community for Communication details, Fixes

issue #21

* Signed-off by Arul Kumaran <arulkumaran.devarajan@huawei.com>

readme/Communication in Community.rst

@@ -3,16 +3,20 @@
 Communication in Community
 ##########################
 
-If you encounter any problems when using |main_project_name|, please join the email group for discussion.
+`GitLab Mattermost <https://mattermost.com/>`__ is used as the primary communication tool by project members, contributors, and the community. 
 
-How Do I Subscribe to a Mail List?
-**********************************
+For any communication about |main_project_name|, user can sign up using GitLab credentials and join the community chat at mattermost using the URL https://chat.ostc-eu.org/.
 
-If you have never subscribed to a mail list before, follow the steps below:
+If you encounter any problems when using |main_project_name|, join `town-square <https://chat.ostc-eu.org/ostc/channels/town-square>`__ group for discussion.
 
-#. Click the name of the mail list that you want to subscribe to.
-#. Wait until the browser goes to the subscription page of the mail list, which provides instructions on how to subscribe.
-#. Read the subscription instructions and provide an email address that you want to use to subscribe to the mail list.
-#. Enter your email address and click **Subscribe**. You will receive an email asking you to confirm the subscription.
-#. Reply the email to confirm your subscription.
-#. At last, you will receive a welcome email from the email list.
+Bug reports and issues can be raised and tracked in https://git.ostc-eu.org/OSTC/OHOS/meta-ohos/-/issues. 
+
+How Do I Subscribe to Mattermost?
+*********************************
+To join a Public channel, perform the following steps:
+
+#. Select the **+** symbol at the top of the sidebar.
+#. Select Browse Channels and search through the list of Public channels.
+#. Select Join to join the communication channel.
+
+For more details on Mattermost subscription, see https://docs.mattermost.com/guides/user.html.