Gradle task to remove all generated code from doc

[nikitinas]

It would be nice to have gradle task that removes generated samples from doc.
This will simplify documentation review.
And also it's better not to store generated samples in version control, especially when generated code contains special tags that can not be processed by default markdown viewer.

Input

docs.md

<!---test-->
sample code
<!---END-->

Task

gradle korroClean

Output

docs.md

<!---test-->