chore: adding info about collector compatible version, removing duplicated doc after merge (#1361)

* chore: adding info about collector compatible version, removing duplicated doc after merge

* chore: reviews

Author: obecny

packages/opentelemetry-exporter-collector/README.md

@@ -6,7 +6,7 @@
 [![devDependencies][devDependencies-image]][devDependencies-url]
 [![Apache License][license-image]][license-image]
 
-This module provides exporter for web and node to be used with [opentelemetry-collector][opentelemetry-collector-url].
+This module provides exporter for web and node to be used with [opentelemetry-collector][opentelemetry-collector-url] - last tested with version **0.6.0**.
 
 ## Installation