Resolves #367

I've tested locally and it works surprisingly! If I add the following entries to the TOML configuration file (it works even if I already have files = [ { ... } ] entry):

[[files]]
path = "src/MyLib.hs"
raw = '''
module MyLib where

myFunc :: IO ()
myFunc = putStrLn "Hello world!"
'''

[[files]]
path = "test/Doctest.hs"
raw = '''
module Main (main) where

import System.FilePath.Glob (glob)
import Test.DocTest (doctest)


main :: IO ()
main = do
    sourceFiles <- glob "src/**/*.hs"
    doctest sourceFiles
'''

I can even see the files in the TUI structure. And I verifed content after creating the project, the content is perfect 👌

Checklist:

• Update CHANGELOG
  • summoner-cli/CHANGELOG.
  • summoner-tui/CHANGELOG.

• Keep code style used in the changed files (see style-guide for more details).
• Use the stylish-haskell file.
• Update documentation (README, haddock) if required.
• Create a new test project using summoner and check that the changes work as expected.

Hint: Add the [ci skip] text to the docs-only related commit's name, so no need to wait for CI to pass.