Move project options to their own template and start documenting them
    
    This commit moves the entire section about project options into their
    own template, which reduces the amount of code in the settings template.
    In addition it adds a little bit of documentation about the different
    options present and what they mean in a way that the user can show/hide
    on demand.
    
    Signed-off-by: Pierre-Yves Chibon <pingou@pingoured.fr></pingou@pingoured.fr>