Cleanup build script locations

Some developer scripts ended up in the demonstration scripts directory
that was bundled with builds.  This moves them to the build_tools
directory and updates the associated Documentation

Fixes: lp:1815891
* https://bugs.launchpad.net/kicad/+bug/1815891

CMakeModules/Findngspice.cmake

@@ -47,7 +47,7 @@ if( ${NGSPICE_INCLUDE_DIR} STREQUAL "NGSPICE_INCLUDE_DIR-NOTFOUND" OR ${NGSPICE_
     message( "Most of ngspice packages do not provide the required libngspice library." )
     message( "You can either compile ngspice configured with --with-ngshared parameter" )
     message( "or run a script that does the job for you:" )
-    message( "  cd ./scripts" )
+    message( "  cd ./scripting/build_tools" )
     message( "  chmod +x get_libngspice_so.sh" )
     message( "  ./get_libngspice_so.sh" )
     message( "  sudo ./get_libngspice_so.sh install" )

README.txt

@@ -40,8 +40,8 @@ polygon           - Sourcecode of the polygon library
 potrace           - Sourcecode of the potrace library, used in bitmap2component
 qa                - Testcases using the python interface
 resources         - Resources for freedesktop mime-types for linux
-scripting         - SWIG Python scripting definitions
+scripting         - SWIG Python scripting definitions and build scripts
-scripts           - Helper scripts for various things
+scripts           - Example scripts for distribution with KiCad
 template          - Project and pagelayout templates
 tools             - Other miscellaneous helpers for testing
 utils             - Small utils for kicad, e.g. IDF tools