Update README.md

The Rel-16 branch represents the latest Rel-16 content approved and published after each TSG SA plenary. 

Rel17-draft branch represents the current working in progress release status.

Rel-17 branch represents the current working in progress release status.

(c) 2020, 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TSDSI, TTA, TTC). 

All rights reserved.

Branch {+Rel17-draft+} validation status:

Branch {+Rel-17+} validation status:

[![pipeline status](https://forge.3gpp.org/rep/SA5/MnS/badges/Rel17-draft/pipeline.svg)](https://forge.3gpp.org/rep/SA5/MnS/commits/Rel17-draft)

[![pipeline status](https://forge.3gpp.org/rep/SA5/MnS/badges/Rel-17/pipeline.svg)](https://forge.3gpp.org/rep/SA5/MnS/commits/Rel-17)

## Data models validation

The YANG data models in the present projects are validated by an automated CI agent. Learn more at:

* [Jenkins job run for this project](https://forge.3gpp.org/jenkins/view/SA5/)

* [Validation scripts repository](https://forge.3gpp.org/rep/tools/3gpp-scripts)

* [Management And Orchestration APIs Wiki](https://forge.3gpp.org/rep/sa5/MnS/-/wikis/home)

* [Validation scripts repository](https://forge.3gpp.org/rep/tools/3gpp-scripts/sa5)