Add underscored docs files to Jekyll include

[eritbh]

If Typedoc generates docs files that start with underscores, Jekyll ignores them by default because it ignores all files and folders that start with underscores. Jekyll's include config key can be used to get around this, but it doesn't support glob patterns - only individual files. To work around this, the doc gen script manually adds all underscored files in the generated docs to the include option when pushing the new docs version.