Add lint step to pull request workflow

.github/workflows/pull-request.yml

@@ -0,0 +1,25 @@
+on: 
+  pull_request:
+    branches:
+      - master
+      - dev
+      
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2
+    - name: Set up .NET
+      uses: actions/setup-dotnet@v4
+      with:
+        dotnet-version: 8.0.x
+    - name: Restore dependencies
+      run: dotnet restore src/DotTiled.sln
+    - name: Build
+      run: dotnet build --no-restore src/DotTiled.sln
+    - name: Test
+      run: dotnet test --no-build --verbosity normal src/DotTiled.sln
+    - name: Lint
+      run: |
+        dotnet format style --verify-no-changes --verbosity diagnostic src/DotTiled.sln
+        dotnet format analyzers --verify-no-changes --verbosity diagnostic src/DotTiled.sln