This utility will embed example source from examples into code blocks in Markdown files.
This is used as a step to ensure that the source in guide code blocks matches exactly to
example source.
The EXAMPLES_DIR environment variable should be set to the absolute path of the examples
directory of the ockam repository.
Pass the file to be checked as an argument to the utility. It will search for any code
blocks that begin with a comment of the form // examples/foo.rs and then print that source.