Add fourmolu + hlint with scripts and git hooks (Atlas-style)

- Create scripts/build, scripts/test, scripts/run, scripts/install-hooks
- Create git-hooks/pre-commit (auto-format staged .hs files)
- Create git-hooks/pre-push (check formatting + hlint before push)
- Handle git worktrees correctly in hook installation
- Run fourmolu on all source files to fix existing formatting

src/Roux/Parser.hs

@@ -4,9 +4,9 @@ Currently a minimal placeholder that splits input into paragraphs and
 treats them as plain-text steps.  Proper inline parsing (ingredients,
 cookware, timers, …) and metadata support will be added incrementally.
 -}
-module Roux.Parser
-    ( parseCookFile
-    ) where
+module Roux.Parser (
+    parseCookFile,
+) where
 
 import Data.List.NonEmpty (NonEmpty ((:|)))
 import Data.Text (Text)
@@ -14,26 +14,30 @@ import qualified Data.Text as T
 
 import Roux.Types
 
--- | Parse a complete @.cook@ file into a 'Recipe'.
---
--- Returns 'Left' with an error message on invalid input (currently never
--- — the placeholder always succeeds).
+{- | Parse a complete @.cook@ file into a 'Recipe'.
+
+Returns 'Left' with an error message on invalid input (currently never
+— the placeholder always succeeds).
+-}
 parseCookFile :: Text -> Either String Recipe
 parseCookFile input =
     let paragraphs = filter (not . T.null) (map T.strip (T.splitOn "\n\n" (T.strip input)))
      in case paragraphs of
             [] ->
-                Right Recipe
-                    { recipeMetadata = emptyMetadata
-                    , recipeSections = Section Nothing (Step [] :| []) :| []
-                    }
+                Right
+                    Recipe
+                        { recipeMetadata = emptyMetadata
+                        , recipeSections = Section Nothing (Step [] :| []) :| []
+                        }
             (p : ps) ->
-                Right Recipe
-                    { recipeMetadata = emptyMetadata
-                    , recipeSections = Section Nothing (stepFromText p :| fmap stepFromText ps) :| []
-                    }
+                Right
+                    Recipe
+                        { recipeMetadata = emptyMetadata
+                        , recipeSections = Section Nothing (stepFromText p :| fmap stepFromText ps) :| []
+                        }
 
--- | Turn a paragraph of text into a single 'Step' containing nothing but
--- 'StepText'.  This is a placeholder until inline parsing is implemented.
+{- | Turn a paragraph of text into a single 'Step' containing nothing but
+'StepText'.  This is a placeholder until inline parsing is implemented.
+-}
 stepFromText :: Text -> Step
 stepFromText t = Step [StepText t]