doc: remove platform assumption from CONTRIBUTING

- Specify that the ‘make test’ commands are Unix/OS X specific.
- Link to BUILDING.md for other platform commands.

Fixes: #7646

CONTRIBUTING.md

@@ -135,23 +135,35 @@ $ git fetch upstream
 $ git rebase upstream/master
 ```
 
-
 ### Step 5: Test
 
 Bug fixes and features **should come with tests**. Add your tests in the
 `test/parallel/` directory. For guidance on how to write a test for the Node.js
 project, see this [guide](./doc/guides/writing_tests.md). Looking at other tests
 to see how they should be structured can also help.
 
+To run the tests on Unix / OS X:
+
 ```text
 $ ./configure && make -j8 test
 ```
 
+Windows:
+
+```text
+> vcbuild test
+```
+
+(See the [BUILDING.md](./BUILDING.md) for more details.)
+
 Make sure the linter is happy and that all tests pass. Please, do not submit
 patches that fail either check.
 
-Running `make test` will run the linter as well unless one or more tests fail.
-If you want to run the linter without running tests, use `make lint`.
+Running `make test`/`vcbuild test` will run the linter as well unless one or
+more tests fail.
+
+If you want to run the linter without running tests, use 
+`make lint`/`vcbuild jslint`.
 
 If you are updating tests and just want to run a single test to check it, you
 can use this syntax to run it exactly as the test harness would: