Declare obsolete certain things in the design docs

devdoc/NC_design.txt

@@ -1,3 +1,15 @@
+     _________________________________________________________________
+
+                     OBSOLETE -- Flenser is moving to C++23
+     _________________________________________________________________
+
+
+   Descriptions of organization of where files are and such are still
+   somewhat accurate.  However, all style and coding rules are hereby
+   repealed.  Coding whitespace style will follow local norms, until C
+   memory management is mostly removed.  All structural and process
+   rules regarding memory management, etc. are repealed in favour of
+   modern C++ best practices.
 
      _________________________________________________________________