kdoc improvements: added discovery of ReadMe.md or ReadMe.html files in a package source directory, so we can auto-discover documentation like this https://github.com/JetBrains/kotlin/blob/master/libraries/stdlib/src/kotlin/ReadMe.md and fixed a regression where we could not find the KPackage of a descriptor with changes to the AST

libraries/tools/kdoc-maven-plugin/src/main/java/org/jetbrains/kotlin/maven/doc/KDocMojo.java

@@ -143,7 +143,7 @@ public class KDocMojo extends KotlinCompileMojoBase {
     /**
      * A Map of package name to file names for the description of packages.
      * This allows you to refer to ReadMe.md files in your project root directory which will then be included in the API Doc.
-     * For packages which are not configured, KDoc will look for package.html or package.md files in the source directory
+     * For packages which are not configured, KDoc will look for ReadMe.html or ReadMe.md files in the package source directory
      *
      * @parameter expression="${packageDescriptionFiles}"
      */