Each theme lives in a folder, e.g., `themes/informatic` or `themes/modern`. The folder contains individual template files assembled by the theme author. Each template can be used to generate a single type of output file such as HTML, Word, or PDF. Template files are named according to this scheme...
[ OuputFormat ].[ InputFormat ]
...where `[OuputFormat]` and `[InputFormat]` are both one of `html`, `pdf`, `md`, `txt`, `doc`, or `xml`. For example:
-`html.html` = An HTML template used to generate an HTML document.
-`doc.xml` = An XML template used to generate an MS Word document.
-`pdf.html` = An HTML template used to generate a PDF document.
-`md.txt` = A text template used to generate a Markdown document.
This scheme ensures that theme template files have the "correct" file extension when the theme author is working with them in an editor—if your source data is XML then the template file will have an `.xml` extension regardless of whether you're ultimately generating an HTML page or a PDF document *from* that XML. It also provides a declarative mapping between a given input format (say, XML) and a given output file type (say, a Word doc or spreadsheet).
