Update README.md

(cherry picked from commit c04796fd)

README.md

-# Test repo for TS 33.128
+# 3GPP SA3-LI - Trial repository
 
-Test area for experimenting with what to put on the Trial area...
+Trial repository for the 3GPP SA3-LI working group.
\ No newline at end of file
+
+## Guides and How-To
+
+Visit the [Wiki](https://forge.etsi.org/rep/3GPP/SA3LI/wikis/home) for guides on how to:
+* [Log in to the Forge](https://forge.etsi.org/rep/3GPP/SA3LI/wikis/Logging%20in%20to%20the%20Forge)
+* [Join the project](https://forge.etsi.org/rep/3GPP/SA3LI/wikis/Joining%20a%20project)
+* [Make a CR](https://forge.etsi.org/rep/3GPP/SA3LI/wikis/Making%20a%20CR)
+
+Don't see a page on something you think should be documented? Then create one!
+
+## Contribute to the discussion
+
+Visit the [Issues](https://forge.etsi.org/rep/3GPP/SA3LI/issues) page and give
+your thoughts and feedback on how we should use the Forge in SA3-LI.
+
+Have a question that you don't see an Issue for? Then [create one](https://forge.etsi.org/rep/3GPP/SA3LI/issues/new?issue%5Bassignee_id%5D=&issue%5Bmilestone_id%5D=)!
+
+## Licence
+
+(c) 2019, 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TSDSI, TTA, TTC).
+All rights reserved.
\ No newline at end of file