Adding Release Notes

Signed-off-by: Raphael Defosseux <raphael.defosseux@eurecom.fr>

CHANGELOG.md

 # RELEASE NOTES: #
 
+## [v1.2.2](https://gitlab.eurecom.fr/oai/openairinterface5g/-/tags/v1.2.2) -> August 2020. ##
+
+* Bug fix for supporting multi-antennas in RF simulator
+
 ## [v1.2.1](https://gitlab.eurecom.fr/oai/openairinterface5g/-/tags/v1.2.1) -> February 2020. ##
 
 * Bug fix for mutex lock for wake-up signal

CONTRIBUTING.md

@@ -5,8 +5,9 @@ We want to make contributing to this project as easy and transparent as possible
 Please refer to the steps described on our website: [How to contribute to OAI](https://www.openairinterface.org/?page_id=112)
 
 1. Sign and return a Contributor License Agreement to OAI team.
-2. Create an account on [Eurecom GitLab Server](https://gitlab.eurecom.fr).
-3. Provide the identifiant of this account to the OAI team (mailto:contact@openairinterface.org) so you have developer rights on this repository.
+2. We recommend that you provide us with a professional or student email address 
+2. Register on [Eurecom GitLab Server](https://gitlab.eurecom.fr/users/sign_in)
+3. Provide the OAI team with the **username** of this account to (mailto:contact@openairinterface.org) ; we will give you the developer rights on this repository.
 4. The policies are described in these wiki pages: [OAI Policies](https://gitlab.eurecom.fr/oai/openairinterface5g/wikis/oai-policies-home)
    -  PLEASE DO NOT FORK the OAI repository on your own Eurecom GitLab account. It just eats up space on our servers.
    - You can fork onto another hosting system. But we will NOT accept a merge request from a forked repository.