RFC: Allow multiple settings files to be merged into one.

[rochacbruno]

Targeting plugin based applications take as example:

Configuration for general program is in export SETTINGS_FOR_DYNACONF=/etc/program/settings.ext (ext being any of the supported formats yaml, json, ini, toml etc)

That same program has plugins and plugin stores its settings under different path like /etc/plugin_name/settings.yaml

RFC: Allow include of settings files in different formats.

Then /etc/program/settings.yaml

DEFAULT:
    DYNACONF_INCLUDE:
        - /etc/plugin_name/settings.yaml
        - /etc/other_plugin_name/settings.toml
        - /etc/settings_folder/* 

or toml

[default]
dynaconf_include = ["path1", "path2"]

or json

{
   "default": {
        "dynaconf_include": ["path1", "path2"]
    }
}

then All the loaders will take the special DYNACONF_INCLUDE key then load values from each of the files listed using the normal pipeline.

Requirements

• Backwards compatibility
• Multiple [envs] should be considered
• Preserve the ordering
• Nested includes should have a maximum recursion level
• When the path is a directory, glob should be used and load in alpha order
• All file formats should be supported, the functionality should be in BaseLoader