Show full code filepaths, and move filepaths from comment to div

Sometimes the comment at the top can break the file (config main.xml)

The more controversial change is an embedded <style> tag that formats the filenames. I can either make it an include for all docs/widget/ pages, or we can add it to aether css. Basically if we add <div class="filepath">contents/ui/configGeneral.qml</div> in front of the code tag it looks like this. The reason for using this is because XML doesn't like it when you have a comment at the start of the file.

This CSS should probably be added to aether css, but I would be okay with just making it an include for the extend/plasma/... sections.