Use examples to create unit tests with validator

linkml-validate -s dist/m30ml.yaml -C Element src/data/examples/001-ExampleElement.yaml

Desired outcomes

[ ] folders & file names should follow same naming convention (as per npm package naming convention) for running test suite - where directories contain a suite of test cases & files are individual test cases. 3 digit integer with leading zeros of what test no. counter followed by a -, followed by keyword valid or invalid to be used for expected output of validator (unless it's a folder name), followed by a -, followed by test case name (as lowercase and _ separated) - e.g., 001-elements/001-valid-example_element.yaml
[ ] tests s/b able to recursively run tests on a directory or single file passed as an argument
[ ] tests should include assertions as to its expected validator output using comment (prepended using a #) on first line
[ ] tests should output YAML file of test log that can be piped into a template for rendering log as markdown