Add lint workflow

.github/workflows/lint.yml

@@ -0,0 +1,30 @@
+name: Lint
+on: [push, pull_request]
+
+jobs:
+  tflint:
+    name: TFLint
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@master
+      - name: TFLint
+        uses: docker://wata727/tflint
+
+  fmt:
+    name: Code Format
+    runs-on: ubuntu-latest
+    container:
+      image: hashicorp/terraform:latest
+    steps:
+      - uses: actions/checkout@master
+      - run: terraform fmt --recursive -check=true
+
+  docs:
+    name: Docs
+    runs-on: macos-latest
+    steps:
+      - uses: actions/checkout@master
+      - name: Install Deps
+        run: brew update && brew install pre-commit terraform-docs terraform
+      - name: Check Docs
+        run: pre-commit run --show-diff-on-failure --all-files terraform_docs