Add GitHub actions CI

.github/workflows/build.yml

@@ -0,0 +1,16 @@
+name: build
+on: [push, pull_request]
+jobs:
+  build:
+    runs-on: windows-latest
+    steps:
+    - uses: actions/checkout@v1
+    - name: Run nmake
+      run: |
+        call "C:\Program Files (x86)\Microsoft Visual Studio\2019\Enterprise\VC\Auxiliary\Build\vcvars64.bat"
+        nmake
+      shell: cmd
+    - uses: actions/upload-artifact@v1
+      with:
+        name: winscap
+        path: winscap.exe

README.md

@@ -1,4 +1,4 @@
-# `winscap`
+# `winscap` [![][1]][2]
 
 Windows raw sound output capture tool.
 
@@ -22,7 +22,7 @@ You need a new enough Visual C++ toolchain. To build, run
 
 ## Background
 
-I created this tool as a lightweight approach to run [Cava][1] on Windows Subsystem
+I created this tool as a lightweight approach to run [Cava][3] on Windows Subsystem
 for Linux (WSL) while using sound output from Windows.
 
 To use with Cava, configure Cava to read from a named pipe inside WSL (we'll use
@@ -45,4 +45,6 @@ $ /mnt/c/path/to/winscap.exe 2 48000 16 > /tmp/cava.fifo
 
 Again, replace the arguments as appropriate.
 
-  [1]: https://github.com/karlstav/cava
+  [1]: https://github.com/quantum5/winscap/workflows/build/badge.svg
+  [2]: https://github.com/quantum5/winscap/actions
+  [3]: https://github.com/karlstav/cava