Splits nimrod and lazarus files into separate directories.

examples/cross_calculator/nimrod_backend/backend.nim

@@ -1,4 +1,4 @@
-# Backend for the Lazarus GUI
+# Backend for the different user interfaces.
 
 proc myAdd*(x, y: int): int {.cdecl, exportc.} = 
   result = x + y

examples/cross_calculator/readme.txt

@@ -0,0 +1,11 @@
+The cross platform calculator illustrates how to use Nimrod to create a backend
+called by different native user interfaces.
+
+Since the purpose of the example is to show how the cross platform code
+interacts with Nimrod the actual backend code is just a simple addition proc.
+By keeping your program logic in Nimrod you can easily reuse it in different
+platforms.
+
+To avoid duplication of code, the backend code lies in a separate directory and
+each platform compiles it with a different custom build process, usually
+generating C code in a temporary build directory.