chore: add CI

.github/workflows/ci.yml

@@ -0,0 +1,23 @@
+name: Format and lint
+on: [push, pull_request]
+
+jobs:
+  format:
+    name: stylua
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: JohnnyMorganz/stylua-action@1.0.0
+        with:
+          token: ${{ secrets.GITHUB_TOKEN }}
+          args: --check .
+
+  lint:
+    name: selene
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: NTBBloodbath/selene-action@v1.0.0
+        with:
+          token: ${{ secrets.GITHUB_TOKEN }}
+          args: --display-style=quiet .