Build manual

The Jami build manual documents the various aspects of building Jami from source, as well as packaging Jami for various package systems. This manual is aimed at those looking to build Jami from source – for instance to hack on Jami and contribute to its development, or to try recently-added unreleased features – as well as package maintainers and contributors to GNU/Linux distributions looking to package or help maintain a Jami package for their distribution’s repositories.