CI: Install SDL SDK in windows workers and add SDL examples to the build.
CI: Add Vulkan GLFW and SDL builds to windows build job.
diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index cbe8291..1ee3e0d 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -7,11 +7,22 @@
     runs-on: windows-2019
     env:
       MSBUILD_PATH: C:\Program Files (x86)\Microsoft Visual Studio\2019\Enterprise\MSBuild\Current\Bin\
+      # Until gh-actions allow us to use env variables inside other env variables (because we need %GITHUB_WORKSPACE%) we have to use relative path to imgui/examples/example_name directory.
+      SDL2_DIR: ..\..\SDL2-devel-2.0.10-VC\SDL2-2.0.10\
+      VULKAN_SDK: ..\..\vulkan-sdk-1.1.121.2\
     steps:
       - uses: actions/checkout@v1
         with:
           fetch-depth: 1
 
+      - name: Install Dependencies
+        shell: powershell
+        run: |
+          Invoke-WebRequest -Uri "https://www.libsdl.org/release/SDL2-devel-2.0.10-VC.zip" -OutFile "SDL2-devel-2.0.10-VC.zip"
+          Expand-Archive -Path SDL2-devel-2.0.10-VC.zip
+          Invoke-WebRequest -Uri "https://github.com/ocornut/imgui/files/3789205/vulkan-sdk-1.1.121.2.zip" -OutFile vulkan-sdk-1.1.121.2.zip
+          Expand-Archive -Path vulkan-sdk-1.1.121.2.zip
+
       - name: Fix Projects
         shell: powershell
         run: |
@@ -26,7 +37,6 @@
           }
 
       # Not using matrix here because it would inflate job count too much. Check out and setup is done for every job and that makes build times way too long.
-
       - name: Build Win32 example_glfw_opengl2
         shell: cmd
         run: '"%MSBUILD_PATH%\MSBuild.exe" examples/example_glfw_opengl2/example_glfw_opengl2.vcxproj /p:Platform=Win32 /p:Configuration=Release'
@@ -35,6 +45,26 @@
         shell: cmd
         run: '"%MSBUILD_PATH%\MSBuild.exe" examples/example_glfw_opengl3/example_glfw_opengl3.vcxproj /p:Platform=Win32 /p:Configuration=Release'
 
+      - name: Build Win32 example_glfw_vulkan
+        shell: cmd
+        run: '"%MSBUILD_PATH%\MSBuild.exe" examples/example_glfw_vulkan/example_glfw_vulkan.vcxproj /p:Platform=Win32 /p:Configuration=Release'
+
+      - name: Build Win32 example_sdl_vulkan
+        shell: cmd
+        run: '"%MSBUILD_PATH%\MSBuild.exe" examples/example_sdl_vulkan/example_sdl_vulkan.vcxproj /p:Platform=Win32 /p:Configuration=Release'
+
+      - name: Build Win32 example_sdl_opengl2
+        shell: cmd
+        run: '"%MSBUILD_PATH%\MSBuild.exe" examples/example_sdl_opengl2/example_sdl_opengl2.vcxproj /p:Platform=Win32 /p:Configuration=Release'
+
+      - name: Build Win32 example_sdl_opengl3
+        shell: cmd
+        run: '"%MSBUILD_PATH%\MSBuild.exe" examples/example_sdl_opengl3/example_sdl_opengl3.vcxproj /p:Platform=Win32 /p:Configuration=Release'
+
+      - name: Build Win32 example_sdl_directx11
+        shell: cmd
+        run: '"%MSBUILD_PATH%\MSBuild.exe" examples/example_sdl_directx11/example_sdl_directx11.vcxproj /p:Platform=Win32 /p:Configuration=Release'
+
       - name: Build Win32 example_win32_directx9
         shell: cmd
         run: '"%MSBUILD_PATH%\MSBuild.exe" examples/example_win32_directx9/example_win32_directx9.vcxproj /p:Platform=Win32 /p:Configuration=Release'
@@ -55,6 +85,26 @@
         shell: cmd
         run: '"%MSBUILD_PATH%\MSBuild.exe" examples/example_glfw_opengl3/example_glfw_opengl3.vcxproj /p:Platform=x64 /p:Configuration=Release'
 
+      - name: Build x64 example_glfw_vulkan
+        shell: cmd
+        run: '"%MSBUILD_PATH%\MSBuild.exe" examples/example_glfw_vulkan/example_glfw_vulkan.vcxproj /p:Platform=x64 /p:Configuration=Release'
+
+      - name: Build x64 example_sdl_vulkan
+        shell: cmd
+        run: '"%MSBUILD_PATH%\MSBuild.exe" examples/example_sdl_vulkan/example_sdl_vulkan.vcxproj /p:Platform=x64 /p:Configuration=Release'
+
+      - name: Build x64 example_sdl_opengl2
+        shell: cmd
+        run: '"%MSBUILD_PATH%\MSBuild.exe" examples/example_sdl_opengl2/example_sdl_opengl2.vcxproj /p:Platform=x64 /p:Configuration=Release'
+
+      - name: Build x64 example_sdl_opengl3
+        shell: cmd
+        run: '"%MSBUILD_PATH%\MSBuild.exe" examples/example_sdl_opengl3/example_sdl_opengl3.vcxproj /p:Platform=x64 /p:Configuration=Release'
+
+      - name: Build x64 example_sdl_directx11
+        shell: cmd
+        run: '"%MSBUILD_PATH%\MSBuild.exe" examples/example_sdl_directx11/example_sdl_directx11.vcxproj /p:Platform=x64 /p:Configuration=Release'
+
       - name: Build x64 example_win32_directx9
         shell: cmd
         run: '"%MSBUILD_PATH%\MSBuild.exe" examples/example_win32_directx9/example_win32_directx9.vcxproj /p:Platform=x64 /p:Configuration=Release'