Generalized templates to add support for more pages and custom sections

Hello,

I found your really good looking theme, when I was creating a resume. Thanks for all the work.

However, I wanted more pages and I also wanted to generalize the configuration, so I ended up rewriting a lot of the code. No need to merge it, but here it's linked for you and others.

This rewrite added few key features:

• Add support for multiple pages
• Add support for reorder and move features to columns and pages in config
• Add support for new sections with generic widgets (e.g., awards, certificates and projects use the same widget)

Note that I edited publications formats too. I think I fixed the journal format for IEEE as to my understanding it should be in italic. Ì also added undocumented thesis key as that should not be in italics. However, I'm not super familiar with references styles, so I might have made mistakes. Specially, I was not sure how the spans should or should not be used.