added phase further reading to ex 5 and 6

Author: arielsmoler

tutorials/workshops/algo_design_QCE_tutorial/algo_design_QCE_tutorial_part_I.ipynb

@@ -508,7 +508,8 @@
     "Compute x² in the phase of its state. To actually view the phases of the states simulate the program using state-vector simulation.\n",
     "Expand the quantum program visualization down to the gate-level implementation. How is the 'phase' statement synthesized?\n",
     "Inspect the resulting phases of the different states. Do they match the phase expression?\n",
-    "\n"
+    "\n",
+    "Further reading: [Phase Statement](https://docs.classiq.io/latest/qmod-reference/language-reference/statements/phase/)"
    ]
   },
   {