Noted that it isn't possible to run doctests

Author: sunjay

README.md

@@ -10,6 +10,8 @@ Note that the coverage is deliberately incomplete. That
 way you can [follow the badge link][5] and see how [Codecov][1]
 works. You can view the code there, see hits and misses for coverage, etc.
 
+**As of July 2, 2016, there is [no option to make rustdoc generate a runnable test executable][rustdoc-executable]. That means that documentation tests will not show in your coverage data. If you discover a way to run the doctest executable with kcov, please open an [Issue][issues] and we will add that to these instructions.**
+
 ## Basic Usage
 
 Run your tests with [kcov][6] in order to create the necessary coverage
@@ -130,4 +132,6 @@ learn more about the script.
 [4]: https://github.com/codecov/codecov-bash
 [5]: http://codecov.io/github/codecov/example-rust?branch=master
 [6]: https://simonkagstrom.github.io/kcov/
+[rustdoc-executable][http://stackoverflow.com/questions/35547710/does-rustdoc-generate-runnable-binaries]
+[issues]: https://github.com/codecov/example-rust/issues