Update MacOS setup guide (#691)

1. For M1/M2/etc. devices the homebrew location is slightly different, so note that.

2. For clang, linking to pthreads is slightly different so note that as well.

docs/getting_started/setup/macos.md

@@ -36,8 +36,11 @@ This will generate a `crow_all.h` file which you can use in the following steps
     === "Single Header"
 
         1. Place `crow_all.h` inside your project folder and add it to the project in XCode (you need to use File -> Add files to "project_name")
-        2. Add header search paths for asio's folder (`/usr/local/include`, and `/usr/local/Cellar/asio/include`)
-        3. Add linker flags (`-lpthread`)
+        2. Add header search paths for asio's folder:
+           1. `/usr/local/include`, and
+           2. **Silicon**: `/opt/homebrew/Cellar/asio/<asio_version>/include`
+           3. **Intel**: `/usr/local/Cellar/asio/<asio_version>/include`
+        3. Add linker flags (`-lpthread` for g++, `-pthread` for clang++)
 
 5. Write your Crow application in `main.cpp` (something like the Hello World example will work).
 6. Press `▶` to compile and run your Crow application.