Add MSVS build instructions

Adds instructions on how to generate an MSVS solution.

Bug: dawn:1661
Change-Id: I3433951a3460d6b6392964e4b163060fc100b6c7
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/131881
Reviewed-by: Austin Eng <enga@chromium.org>
Kokoro: Kokoro <noreply+kokoro@google.com>
Commit-Queue: Brandon1 Jones <brandon1.jones@intel.com>
diff --git a/docs/building.md b/docs/building.md
index dc32aad..16fb7b6 100644
--- a/docs/building.md
+++ b/docs/building.md
@@ -73,6 +73,9 @@
 On macOS you'll want to add the `use_system_xcode=true` in most cases.
 (and if you're a googler please get XCode from go/xcode).
 
+To generate a Microsoft Visual Studio solution, add `ide=vs2022` and
+`ninja-executable=<dawn parent directory>\dawn\third_party\ninja\ninja.exe`.
+The .sln file will be created in the output directory specified.
 
 ### Fuzzers on MacOS
 If you are attempting fuzz, using `TINT_BUILD_FUZZERS=ON`, the version of llvm