[K/N] A bit cleaner reflection of code coverage state in docs.

kotlin-native/CODE_COVERAGE.md

@@ -2,10 +2,11 @@
 Kotlin/Native has a code coverage support that is based on Clang's 
 [Source-based Code Coverage](https://clang.llvm.org/docs/SourceBasedCodeCoverage.html).
  
-**Please note**:
-1. Coverage support is in it's very early days and is in active development. Known issues are:
+## **Please note**:
+1. ⚠️ Coverage support is far from being ready for usage. Known issues are:
     * Coverage information may be inaccurate.
     * Line execution counts may be wrong.
+    * The thing might just not work.
 
 2. Most of described functionality will be incorporated into Gradle plugin.
 

kotlin-native/samples/coverage/README.md

@@ -1,5 +1,7 @@
 # Code Coverage usage sample
 
+⚠️ Kotlin/Native support for code coverage is [far from beign ready](../../CODE_COVERAGE.md). Anything might be broken.
+
 This example shows how to collect coverage information during execution of the test suite. 
 Please note that this functionality will be incorporated into Gradle plugin so you won't need to do it by hand in the nearest future.