Write package.yaml instead of hindent.cabal

[toku-sa-n]

The main advantage is that we don't have to list all modules manually.

[mihaimaruseac]

We'll need to always generate the cabal file each time package.yaml changes. But otherwise, the idea of this lgtm

[toku-sa-n]

I thought running stack build generates the cabal file If necessary, but when I ran it after modifying HIndent's version to 5.3.6 in package.yaml, the cabal file was not changed. Maybe we need to ensure the cabal file is up-to-date on CI?

[mihaimaruseac]

Yes, I'm thinking the same

[mihaimaruseac]

Do we want to remove the files in tests? They don't look like doing much, so maybe yes?

[toku-sa-n]

Yes, these files do nothing. Do you prefer another PR for the deletion?

[mihaimaruseac]

It's ok here, just wanted to make sure.