Refactor debugging documentation

The debugging documentation section explains how to debug test binaries
and to enable TDEBUG messages on tests run.

doc_new/developers/debugging.rst

@@ -3,8 +3,19 @@
 Debugging
 =========
 
-The new test library runs the actual test, i.e. the `test()` function in a
+This section explains some tricks which can be used to debug test binaries.
+
+Debug messages
+--------------
+
+The LTP framework currently supports ``TDEBUG`` flag test debug messages. These
+messages can be enabled using the ``-D`` test's argument.
+
+Tracing and debugging syscalls
+------------------------------
+
+The new test library runs the actual test (i.e. the ``test()`` function) in a
 forked process. To get stack trace of a crashing test in gdb it's needed to
 `set follow-fork-mode child <https://ftp.gnu.org/old-gnu/Manuals/gdb/html_node/gdb_25.html>`_.
-To trace the test, please use `strace -f` to enable tracing also for the
+To trace the test, please use ``strace -f`` to enable tracing also for the
 forked processes.