Add fix-whitespace gh-action

Author: philderbeast

.github/workflows/whitespace.yml

@@ -0,0 +1,13 @@
+name: whitespace
+
+on:
+  push:
+  pull_request:
+
+jobs:
+  check:
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v4
+    - uses: andreasabel/fix-whitespace-action@v1

fix-whitespace.yaml

@@ -0,0 +1,11 @@
+excluded-dirs:
+  - "dist-newstyle"
+
+included-files:
+  - "**/*.cabal"
+  - "**/*.dhall"
+  - "**/*.hs"
+  - "**/*.md"
+  - "**/*.project"
+  - "**/*.yaml"
+  - "**/*.yml"