Add Makefile with standard NuttX build system integration. Follows
the MENUDESC + Directory.mk pattern used throughout nuttx-apps.
Enables the system/microros module to be built as part of the apps
directory build process.
Signed-off-by: Arjav Patel <arjav1528@gmail.com>
Add Make.defs with copyright header for the micro-ROS library
build system. This establishes the directory structure for Phase 2,
with actual build logic to follow in subsequent steps.
Signed-off-by: Arjav Patel <arjav1528@gmail.com>