updated readme with release notes

Author: ppescher

Diff for: README.md

@@ -1,11 +1,15 @@
-#OpenTracker - board manager files
+#OpenTracker - Arduino Boards Manager
 
-Arduino IDE Board manager files
-
-The first commercial grade, fully open source and 100% Arduino compatible GPS/GLONASS vehicle tracker with a powerful 32-bit ARM Cortex-M3 CPU.
-
-Official website: [https://www.geolink.io](https://www.geolink.io)
+Works with Arduino IDEs version 1.6.x and later (tested with 1.6.4)
 
+Open the menu "File" > "Preferences" and add the following text to the box "Additional Boards Manager URLs":
+https://cdn.rawgit.com/geolink/opentracker-arduino-board/master/package_opentracker_index.json
 
+**NOTE**
+The link points to the package description file in the "master" branch, that may include new releases in the future.
+Maintainers and contributors, please use a separate branch for new releases, so that the above link does not break inadvertently and a clean merge can be prepared for inclusion in the "master" branch.
 
+###OpenTracker
+The first commercial grade, fully open source and 100% Arduino compatible GPS/GLONASS vehicle tracker with a powerful 32-bit ARM Cortex-M3 CPU.
 
+Official website: [https://www.geolink.io](https://www.geolink.io)