Try to cache windows .stack folder in github action

Author: herrmanno

.github/workflows/main.yml

@@ -20,6 +20,7 @@ jobs:
     - uses: actions/checkout@v2
     - name: Cache-stack
       uses: actions/cache@v2
+      if: matrix.os != 'windows-latest'
       env:
         cache-name: stack
       with:
@@ -29,6 +30,18 @@ jobs:
           ${{ runner.os }}-build-${{ env.cache-name }}-
           ${{ runner.os }}-build-
           ${{ runner.os }}-
+    - name: Cache-stack (Windows)
+        uses: actions/cache@v2
+        if: matrix.os == 'windows-latest'
+        env:
+          cache-name: stack-windows
+        with:
+          path: 'C:\Users\runneradmin\AppData\Local\Programs\stack'
+          key: ${{ runner.os }}-build-${{ env.cache-name }}-${{ hashFiles('**/stack.yaml.lock') }}
+          restore-keys: |
+            ${{ runner.os }}-build-${{ env.cache-name }}-
+            ${{ runner.os }}-build-
+            ${{ runner.os }}-
     - name: Setup Stack
       env:
         ACTIONS_ALLOW_UNSECURE_COMMANDS: true