add swiftlint workflow

Author: lukepistrol

.github/workflows/swiftlint.yml

@@ -0,0 +1,25 @@
+name: SwiftLint
+on:
+  push:
+    branches:
+      - 'main'
+    paths:
+      - '.github/workflows/swiftlint.yml'
+      - '.swiftlint.yml'
+      - '**/*.swift'
+  pull_request:
+    branches:
+      - 'main'
+    paths:
+      - '.github/workflows/swiftlint.yml'
+      - '.swiftlint.yml'
+      - '**/*.swift'
+jobs:
+  SwiftLint:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v1
+      - name: GitHub Action for SwiftLint with --strict
+        uses: norio-nomura/action-swiftlint@3.2.1
+        with:
+          args: --strict