Update FAQ entry on building on non-Windows platforms

doc/cfgfile.rst

@@ -217,6 +217,8 @@ limitations:
   Python. If your application has plugins based on Python packages, this might
   require extra thought about how and where plugins are installed.
 
+.. _cfg_include:
+
 Include section
 ---------------
 

doc/faq.rst

@@ -4,22 +4,36 @@ FAQs
 Building on other platforms
 ---------------------------
 
-NSIS can run on Linux, so you can build Windows installers without running
-Windows. However, if your package relies on compiled extension modules, like
+You can use Pynsist to build Windows installers from a Linux or Mac system.
+You'll need to install NSIS so that the ``makensis`` command is available.
+Here's how to do that on some common platforms:
+
+* Debian/Ubuntu: ``sudo apt-get install nsis``
+* Fedora: ``sudo dnf install mingw32-nsis``
+* Mac with `Homebrew <https://brew.sh/>`__: ``brew install makensis``
+
+Installing Pynsist itself is the same on all platforms::
+
+    pip install pynsist
+
+If your package relies on compiled extension modules, like
 PyQt4, lxml or numpy, you'll need to ensure that the installer is built with
-Windows versions of these packages. There are two ways to do this:
+Windows versions of these packages. There are a few options for this:
 
+- List them under ``pypi_wheels`` in the :ref:`Include section <cfg_include>`
+  of your config file. Pynsist will download Windows-compatible wheels from
+  PyPI. This is the easiest option if the dependency publishes wheels.
 - Get the importable packages/modules, either from a Windows installation, or
   by extracting them from an installer. Copy them into a folder called
-  ``pynsist_pkgs``, next to your ``installer.cfg`` file. pynsist will
+  ``pynsist_pkgs``, next to your ``installer.cfg`` file. Pynsist will
   copy everything in this folder to the build directory.
 - Include exe/msi installers for those modules, and modify the ``.nsi`` template
   to extract and run these during installation. This can make your installer
   bigger and slower, and it may create unwanted start menu shortcuts
-  (e.g. PyQt4 does), so the first option is usually better. However, if the
+  (e.g. PyQt4 does), so it's a last resort. However, if the
   installer sets up other things on the system, you may need to do this.
 
-When running on non-Windows systems, pynsis will bundle a 32-bit version of
+When running on non-Windows systems, Pynsist will bundle a 32-bit version of
 Python by default, though you can override this :ref:`in the config file <cfg_python>`.
 Whichever method you use, compiled libraries must have the same bit-ness as
 the version of Python that's installed.