Add documentation on how to block installation based on OS versions

Attempt on addressing wixtoolset/issues#8785 by extending the WiX documentation to also cover an OS version check that I believe is quite common.

Author: forderud

src/content/docs/wix/tools/launch-checks.md

@@ -0,0 +1,16 @@
+---
+sidebar_position: 91
+---
+
+# How To: Block installation based on OS version
+
+It is often desirable to block installation of an application on too old Windows versions. The following sample demonstrates how to block installation on Windows versions prior to Windows 10 version 21H1.
+
+```xml
+<Property Id="WINDOWSBUILDNUMBER" Secure="yes">
+    <RegistrySearch Id="BuildNumberSearch" Root="HKLM" Key="SOFTWARE\Microsoft\Windows NT\CurrentVersion" Name="CurrentBuildNumber" Type="raw" />
+</Property>
+<Launch Condition="Installed OR (WINDOWSBUILDNUMBER &gt;= 19044)" Message="This application require Windows 10 version 21H1 (build 19044) or newer." />
+```
+
+The sample uses the `SOFTWARE\Microsoft\Windows NT\CurrentVersion\CurrentBuildNumber` registry key to detect the current Windows version.