docs(timing): introduce timing module into docs

docs/index.rst

@@ -30,6 +30,7 @@ GUM-compliant neural network robustness verification
    lp_nn_robustness_verification.data_acquisition
    lp_nn_robustness_verification.data_types
    lp_nn_robustness_verification.linear_program
+   lp_nn_robustness_verification.timing
 
 Indices and tables
 ==================

docs/lp_nn_robustness_verification.timing.rst

+Timing
+======
+
+.. automodule:: lp_nn_robustness_verification.timing
+    :members:
+    :private-members:
\ No newline at end of file