Hook pagination navigation on taxonomy/archive page templates

[arraypress]

At the minute, within the taxonomy (and archive) page templates, the call to the themedd_edd_download_nav function is hard-coded into the template file, to replace this means overriding the template (overkill), I feel it would be better if this was simply hooked so it could be easy removed by child themes.

[amdrew]

@davidsherlock You should be able to remove it for taxonomy pages using the themedd_edd_download_grid_options filter. Since there's already a way to do it I don't think we need to add a hook.

[arraypress]

Close this one off for the time-being, we can revisit it once 1.1 is released if needed.