Add Github CI.

.github/workflows/main.yml

@@ -0,0 +1,37 @@
+# This is a basic workflow to help you get started with Actions
+
+name: CI
+
+# Controls when the workflow will run
+on:
+  pull_request:
+    paths-ignore:
+        - '.gitignore'
+        - README.*
+        - LICENSE
+        - 'etc/**'
+
+  push:
+    # Sequence of patterns matched against refs/tags
+    branches: ["main"]
+    paths-ignore:
+        - '.gitignore'
+        - README.*
+        - LICENSE
+        - 'etc/**'
+
+  # Allows you to run this workflow manually from the Actions tab
+  workflow_dispatch:
+
+# A workflow run is made up of one or more jobs that can run sequentially or in parallel
+jobs:
+  run-tests:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - name: Install GNU Guix
+        uses: PromyLOPh/guix-install-action@v1.5
+
+      # Runs a set of commands using the runners shell
+      - name: Build image
+        run: guix shell make -- make check