message: Update testing docs with info about Apple
  Adding note about using "--demos-binary" option to specify the filepath of the demos binary as an alternative to making sure the demos binary is in the PATH.
  Fixed a typo "can'tbe" -> "can't be"
diff: @@ -8,20 +8,20 @@ A lot of the tests rely on a 'demos' program which contains small self-contained
  To build on windows, open `demos.sln` and compile. There are no required external dependencies
  -To build on linux, compile using cmake with `demos/CMakeLists.txt` ie.
  +To build on linux or Apple, compile using cmake with `demos/CMakeLists.txt` ie.
  ```
  cmake -Bbuild -Hdemos
  make -C build
  ```
  -You'll need `libX11`, `libxcb`, and `libX11-xcb`. These are all needed to build RenderDoc with GL support so you likely have them already.
  +For linux you'll need `libX11`, `libxcb`, and `libX11-xcb`. These are all needed to build RenderDoc with GL support so you likely have them already.
  **NOTE:** Currently there is one soft external dependency. If shaderc is not linked into the demos program, it expects to be able to run `glslc` at runtime to compile shaders to SPIR-V. Without this, some tests will be disabled.
  Currently only windows supports linking shaderc, which happens automatically if it's found relative to the `$VULKAN_SDK` environment variable.
  -On linux to run the tests you'll need to modify your `PATH` variable to include wherever `demos_x64` was built to.
  +On linux or Apple to run the tests you'll need to modify your `PATH` variable to include wherever `demos_x64` was built to, alternatively the `--demos-binary` option can be used to specific the filepath of `demos_x64`.
  ## Running tests
  @@ -41,6 +41,7 @@ Then running the tests means invoking `run_tests.py` with any options you need:
  * `--artifacts` the path to the output artifacts folder, by default `artifacts/` here next to the script.
  * `--temp` the path to the temporary working folder, by default `tmp/` here next to the script.
  * `--data-extra` the path to the extra data folder. Some tests may reference captures which can't be committed to the repository here and are distributed separately or added custom by the user. By default refers to `data_extra/` here next to the script.
  +* `--demos-binary` the path to the built demos binary.
  **NOTE:** When run, the temporary and artifacts folders will be erased.
  