update vxserver.dev to fsdproject.org

docs.fsdproject.org/include/header.lua

@@ -0,0 +1,9 @@
+local header = {}
+
+header.render = function(std)
+    return table.concat({
+        std.center(std.ha("/", std.h1("Free Software Distributions Project documentation"))),
+    })
+end
+
+return header