`locations` is a dictionnary of location block. `location` (the key of an item) is the location (eg, "/"), `template` are the jinja templates defining the contant of the location block. Other variables can be added to the location block depending on the template used. `config` is a string added directly to the config of the location block.
Inside the templates, `server_name` is accessed with `{{ item.key }}`, en variables of the server block with `{{ item.value.varname }}`.
Inside templates of a location, in addition to the variables of the server block, the variables of the location block can be accessed with `{{ location.value.varname }}`, and the value of `location` with `{{ location.key }}`.