update build instructions

docs/source/building/macos.rst

@@ -12,18 +12,27 @@ MacPorts
 Install Requirements
    .. code-block:: bash
 
-      sudo port install cmake boost ffmpeg libopus
+      sudo port install cmake boost ffmpeg libopus npm9
 
 Homebrew
 """"""""
 Install Requirements
    .. code-block:: bash
 
-      brew install boost cmake ffmpeg opus
+      brew install boost cmake ffmpeg node opus
       # if there are issues with an SSL header that is not found:
       cd /usr/local/include
       ln -s ../opt/openssl/include/openssl .
 
+npm dependencies
+----------------
+Install npm dependencies.
+   .. code-block:: bash
+
+      pushd ./src_assets/common/assets/web
+      npm install
+      popd
+
 Build
 -----
 .. Attention:: Ensure you are in the build directory created during the clone step earlier before continuing.