readme DOC add deprecation notice

Author: michalvasko

README.md

@@ -18,15 +18,10 @@ Monitoring and Configuration](https://www.liberouter.org/) department of
 [CESNET](http://www.ces.net/). Any feedback, testing or feature requests are welcome.
 Please contact us via the [issue tracker](https://github.com/CESNET/Netopeer2/issues).
 
-## Branches
+## Deprecation Notice
 
-The project uses 2 main branches `master` and `devel`. Other branches should not be cloned. In `master` there are files of the
-last official *release*. Any latest improvements and changes (of the server), which were tested at least briefly are found
-in `devel`. On every new *release*, `devel` is merged into `master`.
-
-This means that when only stable official releases are to be used, either `master` can be used or specific *releases* downloaded.
-If all the latest bugfixes should be applied, `devel` branch is the  one to be used. Note that whenever **a new issue is created**
-and it occurs on the `master` branch, the **first response will likely be** to use `devel` before any further provided support.
+Netopeer2 version 1 is deprecated and while still being supported, no new features or complex bugfixes
+will be implemented. It is recommended to switch to using version 2.
 
 ## Packages