Add cache

.github/workflows/build.yml

@@ -0,0 +1,24 @@
+name: Build
+
+on:
+  push:
+    branches: ['master']
+
+jobs:
+  build:
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix:
+        os: [macos-latest, ubuntu-latest]
+    steps:
+    - uses: actions/checkout@v3
+    - uses: cachix/install-nix-action@v16
+      with:
+        nix_path: nixpkgs=channel:nixpkgs-unstable
+    - uses: cachix/cachix-action@v10
+      with:
+        name: nifoc
+        signingKey: '${{ secrets.CACHIX_SIGNING_KEY }}'
+    - run: nix build '.#cliclick'
+    - run: nix build '.#proximity-sort'
+    - run: nix build '.#q'