Currently, we've hardcoded some of the files in the .toml config, for example:

stylish.url = "https://raw.githubusercontent.com/kowainik/org/master/.stylish-haskell.yaml"
contributing.url = "https://raw.githubusercontent.com/kowainik/org/master/CONTRIBUTING.md"

This approach is not extensible because:

1. It doesn't allow summoner users to bring their own files.
2. It requires to change Haskell code each time we want to add new files.

Since tomland-1.1 we now have the support for inline tables. And after this issue is implemented we can have only single field in the config of the type Map FilePath Source and in the configuration it will look like this:

extra.files =
    [ { file = ".stylish-haskell.yaml", url = "https://raw.githubusercontent.com/kowainik/org/master/.stylish-haskell.yaml" }
    , { file = "CONTRIBUTING.md", url = "https://raw.githubusercontent.com/kowainik/org/master/CONTRIBUTING.md" }
    ]

What do you think?

The implementation includes:

• Add Map FilePath Source field to config
• Create files from the Map
• Write deprecation messages
• Pretty tree display in TUI