Update XML to markdown conversion process #190

Right now both the generated and manually created coding guidelines go into a single file.

We would like to do the following

• Update the XML to markdown tool to accept more that one file. Combine the contents of all passed into files to generate the markdown.
• Separate out the manually created guidelines from the generated ones. The schema of both of these files should remain the same.
• Update the GitHub action to pass in both files.