Feature/refactor

Added docs and renamed variables for clarity. Modules now make use of RenderResult. Changes to the player allow for multiple renderers and export options. The config file now requires a list of Renderers and a list of exporters rather than just a list of handlers.
Split this line up; it makes it more readable.

```python
def render_docx(fp, *args, **kwargs):
    html_string = pydocx.Docx2Html(fp.name).parsed

    return RenderResult(content=html_string, assets={})