Adding a new image : pandoc/extra

[daamien]

Following the discussion here:
https://groups.google.com/g/pandoc-discuss/c/PgjdS28nz0A

We could add new variant named extra (or maybe something else to avoid confusion with the debian package named texlive-latex-extra ? ).

The purpose of this variant is to provide a batteries included pandoc environment that could generate "nice looking" documents using a curated list of additional components (templates, latex packages, pandoc filters, open-source fonts, etc. ).

This is of course very subjective and we may always receive demands for a specific package or template. The main question would be where do we draw the line ?

Here's a draft of criterias we could use to define how we manage this curated list of components

• The component has been requested for more than one pandoc user
• The component is active and maintained (at least a few commits over the last 3 years ?)
• The component is well-know or used a lot within the pandoc community
• The component does not pose any security risk
• The component brings a feature that is not already present in the extra variant

Based on this, I would say that the eisvogel template and its dependencies would be a great first candidate.

Latex templates are probably the most difficult types of templates to integrate with pandoc and this is an area where docker makes a lot of sense. However in the long run we may also want to add other types of templates (HTML, ODT, etc.)