Use fourmolu instead of stylish-haskell

fourmolu.yaml

@@ -0,0 +1,22 @@
+indentation: 2
+column-limit: 120
+function-arrows: leading
+comma-style: leading
+import-export-style: leading
+import-grouping: by-scope-then-qualified
+indent-wheres: true
+record-brace-space: true
+newlines-between-decls: 1
+haddock-style: single-line
+haddock-style-module: single-line
+haddock-location-signature: auto
+let-style: auto
+in-style: left-align
+single-constraint-parens: always
+single-deriving-parens: always
+sort-constraints: false
+sort-derived-classes: false
+sort-deriving-clauses: false
+trailing-section-operators: true
+unicode: never
+respectful: true