LuaJIT platform profiler documentation

Introduce a new document on LuaJIT platform profiler

* LuaJIT platform profiler is a new feature implemented in
  Tarantool 2.10.0. The document describes the profiler's behavior
  as of this and next Tarantool versions.
* The document is placed in the Tooling chapter.

Closes #2587

Author: ligurio

doc/tooling/index.rst

@@ -11,4 +11,5 @@ to work with Tarantool.
     tcm/index
     interactive_console
     luajit_memprof
+    luajit_sysprof
     luajit_getmetrics