Reviewed build.txt with editorial changes

Author: floriankirsch

build.txt

@@ -14,22 +14,13 @@ opencsgexample.exe has been built. Be sure to pick the correct
 64- or 32-bit version of the dll.
 
 
-Microsoft Visual Studio 6
--------------------------
-
-The Visual Studio 6 solution OpenCSG.dsw assumes that the original
-GLUT for Windows is setup as described in
-https://user.xmission.com/~nate/glut.html
-
-The solution automatically builds the opencsg lib, and the example.
-
-
 Linux
 -----
 
 1) As prerequisites, you must install OpenGL development packages,
    and, for the example application, glut. To create the makefiles,
    additionally you need CMake.
+
 2) Just type:
 
    cmake CMakeLists.txt
@@ -52,6 +43,16 @@ Linux
    to /usr/local)
 
 
+Microsoft Visual Studio 6
+-------------------------
+
+The Visual Studio 6 solution OpenCSG.dsw assumes that the original
+GLUT for Windows is setup as described in
+https://user.xmission.com/~nate/glut.html
+
+The solution automatically builds the opencsg lib, and the example.
+
+
 Dev-C++ 5.11
 ------------