Fix Windows path used for test_env in docs.
Actually tested this one, as part of
```
test:vk_swiftshader --test_env="VK_ICD_FILENAMES=D:\\dev\\projects\\iree\\build-swiftshader\\Windows\\vk_swiftshader_icd.json"
```
with `--config=vk_swiftshader` passed to `bazel test`.
diff --git a/docs/GetStarted/getting_started_windows_vulkan.md b/docs/GetStarted/getting_started_windows_vulkan.md
index b76b756..9ceee2a 100644
--- a/docs/GetStarted/getting_started_windows_vulkan.md
+++ b/docs/GetStarted/getting_started_windows_vulkan.md
@@ -102,7 +102,7 @@
this (substitute for the `{}` paths):
```
-test --test_env="VK_ICD_FILENAMES={PATH_TO_IREE}/build-swiftshader/Windows/vk_swiftshader_icd.json"
+test --test_env="VK_ICD_FILENAMES={PATH_TO_IREE}\\build-swiftshader\\Windows\\vk_swiftshader_icd.json"
```
## Using IREE's Vulkan Compiler Target and Runtime Driver
