[Plugins]: New API for using Global Config

[naveen521kk]

Description of the proposed feature

Currently, there is no way for plugins to use the global config dictionary/structure for their own configuration. I propose to add an API or a hook that plugins can use for their own configuration.

Hook Details

The plugins can define a function called manim_add_config which will return a dictionary. The dictionary's key is config name and the dictionary's value should be the type to convert the value to (for example int). The dictionary can have as many config variables as needed. Manim will see if that function is defined in the plugin and then calls it; does the necessary things to add it to the config variable.

def manim_add_config():
    return {
         'test': int
    }

Example

In manim-fonts plugin, I would like to introduce a config var called FONT_DIR which I would expect the user to set using manim.cfg or a CLI flags and the plugin will read it using config variable defined globally in manim.

So I would define a function

def manim_add_config():
    return {
         'FONT_DIR': str
    }

and then read it using

from manim import config
print(config.FONT_DIR)

Additional comments

I think there needs to similar options for plugins to add a command-line flag.