docs: update meson docs for windows

Acked-by: Kristian H. Kristensen <hoegsberg@google.com>
diff --git a/docs/install.html b/docs/install.html
index 4e3d0e4..83c5ebf 100644
--- a/docs/install.html
+++ b/docs/install.html
@@ -37,9 +37,9 @@
 <h4>Build system</h4>
 
 <ul>
-<li><a href="https://mesonbuild.com">meson</a> is required when building on *nix platforms.
-<li><a href="http://www.scons.org/">SCons</a> is required for building on
-Windows and optional for Linux (it's an alternative to meson.)
+<li><a href="https://mesonbuild.com">meson</a> is required when building on *nix platforms and is supported on windows.
+<li><a href="http://www.scons.org/">SCons</a> is an alternative for building on
+Windows and Linux.
 </li>
 <li>Android Build system when building as native Android component. Meson
 is used when when building ARC.
@@ -109,8 +109,7 @@
 
 <p>
 Meson is the latest build system in mesa, it is currently able to build for
-*nix systems like Linux and BSD, macOS, Haiku, and will be able to build for
-windows as well.
+*nix systems like Linux and BSD, macOS, Haiku, and Windows.
 </p>
 
 <p>
@@ -121,6 +120,14 @@
   ninja -C builddir/
   sudo ninja -C builddir/ install
 </pre>
+
+<p>On windows you can also use the visual studio backend</p>
+<pre>
+  meson builddir --backend=vs
+  cd builddir
+  msbuild mesa.sln /m
+</pre>
+
 <p>
 Please read the <a href="meson.html">detailed meson instructions</a>
 for more information