Add CI

Author: doshitan

.github/actions/setup-nix/action.yml

@@ -0,0 +1,12 @@
+name: "Setup Nix"
+description: "Install and configure Nix for Github Actions"
+runs:
+  using: "composite"
+  steps:
+    - uses: nixbuild/nix-quick-install-action@v34
+    - uses: nix-community/cache-nix-action@v7
+      with:
+        # restore and save a cache using this key
+        primary-key: nix-${{ runner.os }}-${{ hashFiles('**/*.nix', '**/flake.lock') }}
+        # if there's no cache hit, restore a cache by this prefix
+        restore-prefixes-first-match: nix-${{ runner.os }}-

.github/workflows/ci.yaml

@@ -0,0 +1,18 @@
+name: CI
+
+on:
+  push:
+    branches:
+      - main
+  pull_request:
+  workflow_dispatch:
+
+jobs:
+  ci:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v6
+      - uses: ./.github/actions/setup-nix
+
+      - name: Run lint
+        run: nix develop --command bash -c "make check"