PDF for appendix documents, yaml index

[maldins46]

I write this issue as a reminder for the me of the future. I think it could be better to generate also a separate pdf for the appendix documents of the repository, as they are part of the documentation, actually. They should be merged into a single document.

As a further optimization, it could be nice to have a sort of index for each repo, written in Yaml, as I have seen it could be done easily. This could make the order of the chapters independent of their name.

In addition, a separate Yaml fine should be used also to store metadata, instead of including them inside documents. I think this would make the files cleaner, and also easier to read from the GitHub standard interface for markdown.