Add simple CI pipeline

.github/workflows/ci.yml

@@ -0,0 +1,34 @@
+name: CI
+
+# Trigger the workflow on push or pull request, but only for the master branch
+on:
+  pull_request:
+  push:
+    branches: [master]
+    tags:
+      - "v*"
+  workflow_dispatch:
+
+# INFO: The following configuration block ensures that only one build runs per branch,
+# which may be desirable for projects with a costly build process.
+# Remove this block from the CI workflow to let each CI job run to completion.
+concurrency:
+  group: build-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  lint:
+    name: General linting steps
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: cachix/install-nix-action@v27
+
+      - name: nix flake check
+        run: nix flake check
+
+      - name: treefmt - check format
+        run: nix fmt -- --ci
+
+      - name: Haskell build
+        run: nix build .