Update readme

Update README with relevant information of "how to" interact with documentation.

doc/index.md

 <img src="images/logos/OpenCAPIF.png" alt="drawing" width="200"/>
 
+# Release X.X.X-rc
+
+This release includes next changes:
+- New register flow to ensure:
+  - isolation between CCF and Register services.
+  - Improve security, with split resposability between administrator operations and common user.
+- Improved Testing with Robot in order to cover:
+  - New Register flows.
+  - Allow different URLs for register, ccf and vault services.
+- Improved security on DB:
+  - Credentials requested to access mongo databases.
+  - Credentials requested also by mongo-express.
+- Scripts upgraded:
+  - docker compose version 2 used on them.
+  - New cleaning script developed.
+- Cleanup of capif repository:
+  - Documentation is now on splitted repository [OCF Documentation Repository]
+  - Test plan was moved to [OCF Documentation Repository]
+  - Some obsolote data is removed.
+
+
 # Release 0.0
 
 The APIs included in Release 0.0 are:
@@ -133,4 +154,5 @@ Frequently asked questions can be found here: [FAQ Section]
 
 [Open API Descriptions of 3GPP 5G APIs]: https://forge.3gpp.org/rep/all/5G_APIs  "Open API Descriptions of 3GPP 5G APIs"
 [OpenCAPIF Repository]: https://labs.etsi.org/rep/ocf/capif "OpenCAPIF Repository"
-[POSTMAN Section]: ./testing/postman/README.md "POSTMAN Section"
+[POSTMAN Section]: ./testing/postman/README.md "POSTMAN Section"
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+[OCF Documentation Repository]: https://labs.etsi.org/rep/ocf/documentation "OCF Documentation Repository"
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