MSVC_NMake/README.txt: Mention about static builds

diff --git a/MSVC_NMake/README.txt b/MSVC_NMake/README.txt
index d3ba16f..5438335 100644 (file)
--- a/MSVC_NMake/README.txt
+++ b/MSVC_NMake/README.txt
@@ -45,6 +45,10 @@ PREFIX: Optional.  Base directory of where the third-party headers, libraries
         $(X) is the short version of the Visual Studio used, as follows:\r
         2017: 15\r
 \r
+STATIC: Optional.  Set if building libsigc++ as a static library. Note that\r
+        for building items that use this static build, /DLIBSIGCXX_STATIC\r
+        must be passed into the compiler flags.\r
+\r
 USE_COMPAT_LIBS: Build the sigc++ DLL and .lib with the filename\r
                  'sigc-vc150(d)-3_0' for all builds.  This is for\r
                  compatibility reasons, if re-building dependent code is not\r