Fixed protoc path + added cache

.appveyor.yml

@@ -0,0 +1,31 @@
+version: 2.4.{build}
+
+configuration:
+  - Release
+
+image:
+  - Visual Studio 2022
+
+environment:
+  VCPKGDIR: C:\tools\vcpkg\installed\x64-windows
+  matrix:
+  - QTDIR: C:\Qt\5.15\msvc2019_64
+  - QTDIR: C:\Qt\6.5\msvc2019_64
+
+install:
+- cmd: |-
+    set PATH=%QTDIR%\bin;%VCPKGDIR%\tools\protobuf;%PATH%
+    call "C:\Program Files\Microsoft Visual Studio\2022\Community\VC\Auxiliary\Build\vcvars64.bat
+    vcpkg install protobuf:x64-windows
+    vcpkg install zlib:x64-windows
+
+build_script:
+- cmd: |-
+    qmake PROTOBUF=%VCPKGDIR% ZLIB=%VCPKGDIR% pbfplugin.pro
+    nmake release
+
+artifacts:
+- path: pbf.dll
+
+cache:
+- C:\tools\vcpkg\installed\