Broke out the Golang caching examples into Linux/macOS/Windows variants

examples.md

@@ -115,6 +115,8 @@ steps:
 
 ## Go - Modules
 
+### Linux
+
 ```yaml
 - uses: actions/cache@v2
   with:
@@ -126,6 +128,32 @@ steps:
       ${{ runner.os }}-go-
 ```
 
+### macOS
+
+```yaml
+- uses: actions/cache@v2
+  with:
+    path: |
+      ~/Library/Caches/go-build
+      ~/go/pkg/mod
+    key: ${{ runner.os }}-go-${{ hashFiles('**/go.sum') }}
+    restore-keys: |
+      ${{ runner.os }}-go-
+```
+
+### Windows
+
+```yaml
+- uses: actions/cache@v2
+  with:
+    path: |
+      %LocalAppData%\go-build
+      ~/go/pkg/mod
+    key: ${{ runner.os }}-go-${{ hashFiles('**/go.sum') }}
+    restore-keys: |
+      ${{ runner.os }}-go-
+```
+
 ## Haskell - Cabal
 
 We cache the elements of the Cabal store separately, as the entirety of `~/.cabal` can grow very large for projects with many dependencies.