Add GitHub Actions build workflow

.github/workflows/build.yml

@@ -0,0 +1,22 @@
+name: Build
+
+on:
+  push:
+  pull_request:
+  workflow_dispatch:
+
+jobs:
+  windows:
+    name: ${{ matrix.Configuration }} ${{ matrix.Platform }}
+    runs-on: windows-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        Configuration: [.NET Debug, .NET Release, Debug, Release, Unicode Debug, Unicode Release]
+        Platform: [x64, Win32]
+    steps:
+    - uses: actions/checkout@main
+    - uses: microsoft/setup-msbuild@main
+
+    - name: Build
+      run: msbuild /m /p:Configuration="${{ matrix.Configuration }}" /p:Platform="${{ matrix.Platform }}" source/BugTrap.sln

.gitignore

@@ -1,6 +1,7 @@
 # exclude all dot files except .gitignore
 .*
 !.gitignore
+!.github
 
 # exclude binaries and temporary files
 bin/