github: add a linter action

Signed-off-by: Kyle Evans <[email protected]>

.github/workflows/lint.yml

@@ -0,0 +1,25 @@
+name: Lint orch.lua
+on:
+  push:
+    branches: ['*']
+  pull_request:
+    types: [opened, reopened, edited, synchronize]
+
+permissions:
+  contents: read
+
+jobs:
+  build:
+    name: Lint
+    runs-on: ubuntu-latest
+    steps:
+      - name: checkout
+        uses: actions/checkout@v4
+      - name: install system packages
+        run: |
+          sudo apt-get update --quiet || true
+          sudo apt-get -yq --no-install-suggests --no-install-recommends install luarocks
+      - name: install lua packages
+        run: sudo luarocks install luacheck
+      - name: run linter
+        run: make lint