new orgs types in github_repos.json

[mathildedd]

Currently the org type is github by default.
To make the json more flexible, we propose to add a new array:

remote_orgs = ["org_name" = { "type" = "gitlab", "address" = "org_yml.address" }]

that would then contain the info about gitlab repositories, and another type "git" for a yml file containing references to raw git repositories.

Later we could have a follow up to move the current orgs array into this one as well for consistency.

This supposes that each org entity contains repositories of only one type.