Add custom variables to config

[simonedimaria]

Hi everyone!
I'm trying to add custom variable to be able to access them from my partials templates. I tried in different ways, e.g adding my categories.web inside [params] table in hugo.toml file and tried to access it inside my partial template via .Site.Params.categories.web but i get null values. I also tried to add a categories.yaml file inside my /data directory and try to access the variables as .Site.Data.categories.web but still no luck.
How can i accomplish that?

Thanks