A default css stylesheet is included for docs generated in html format.
On second thought, can you create a virtual method to the Generator along the lines of Generator::createResources(ClangDocContext ctx), which would be a no-op for the YAML and MD generators atm and for the HTML generator would encapsulate this logic? I'd rather not have it in the main tool file, since it is generator-specific.
Move the generation of css stylesheet to a function inside the HTMLGenerator.
A virtual function createResources was declared for Generator class. This is no-op for the YAML and MD generators. For the HTML it contains the generation of css stylesheet.