Update docs section on MS Windows binary wheels.

Closes https://bugs.launchpad.net/lxml/+bug/2031023

INSTALL.txt

@@ -106,14 +106,15 @@ the ``CFLAGS`` environment variable::
 MS Windows
 ..........
 
-For MS Windows, recent lxml releases feature community donated
-binary distributions, although you might still want to take a look
-at the related `FAQ entry <FAQ.html#where-are-the-binary-builds>`_.
-If you fail to build lxml on your MS Windows system from the signed
-and tested sources that we release, consider using the binary builds
-from PyPI or the `unofficial Windows binaries
-<http://www.lfd.uci.edu/~gohlke/pythonlibs/#lxml>`_
-that Christoph Gohlke generously provides.
+For MS Windows, we try to provide binary wheels with reasonably up-to-date
+libraries, although you might still want to take a look at the related
+`FAQ entry <FAQ.html#where-are-the-binary-builds>`_.
+Since it is generally difficult to build software on Windows, the library
+versions (libxml2, libxslt, libiconv, zlib) might not always be at the
+same version level as the builds on Linux or macOS.  This usually means
+that the `WinLibs project<https://github.com/orgs/winlibs>`_
+has not updated their repositories yet.  If you need a more recent version,
+please file a ticket on their side to update it.
 
 Linux
 .....

doc/FAQ.txt

@@ -459,21 +459,21 @@ see when (or if) a specific bug has been fixed.
 Where are the binary builds?
 ----------------------------
 
-Thanks to the help by Joar Wandborg, we try to make "manylinux_" binary
-builds for Linux available shortly after each source release, as they
-are very frequently used by continuous integration and/or build servers.
+We provide binaries for Linux (`manylinux`_), macOS and MS Windows
+shortly after each source release.
 
 Thanks to the help by Maximilian Hils and the Appveyor build service,
-we also try to serve the frequent requests for binary builds available
+we try to serve the frequent requests for binary builds available
 for Microsoft Windows in a timely fashion, since users of that platform
 usually fail to build lxml themselves.  Two of the major design issues
 of this operating system make this non-trivial for its users: the lack
-of a pre-installed standard compiler and the missing package management.
+of a pre-installed standard C-compiler and the missing package management.
 
-Besides that, Christoph Gohlke generously provides `unofficial lxml binary
-builds for Windows <http://www.lfd.uci.edu/~gohlke/pythonlibs/#lxml>`_
-that are usually very up to date.  Consider using them if you prefer a
-binary build over a signed official source release.
+We currently rely on the `WinLibs project<https://github.com/orgs/winlibs>`_
+to provide library versions that are buildable on MS Windows.  If the library
+that we use in lxml's Windows binary wheels is outdated, it is probably because
+they have not updated their repositories yet. Consider filing a ticket on their
+side and notifying us when a new version is available, so that we can integrate it.
 
 .. _manylinux: https://www.python.org/dev/peps/pep-0513