Move cplex import to last section

This way, the all parts of the tutorial _except_ the cplex
section will work, even on systems where cplex is unavailable.

docs/tutorials/01_getting_started.ipynb

@@ -36,7 +36,6 @@
    "metadata": {},
    "source": [
     "Next, we import\n",
-    "- CPLEX — an exact classical optimizer we use to evaluate QRAO's approximation.\n",
     "- QRAO — an approximate quantum optimizer to solve combinatorial optimization problems — through a series of 3 classes:\n",
     "  - the encoding class (`QuantumRandomAccessEncoding`), which encodes our problem into a relaxed problem that requires fewer resources to solve\n",
     "  - one rounding scheme (`SemideterministicRounding`), which rounds the solution for the relaxed problem back to a solution of the original problem.\n",
@@ -50,8 +49,6 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "from qiskit_optimization.algorithms import CplexOptimizer\n",
-    "\n",
     "from qrao import (\n",
     "    QuantumRandomAccessEncoding,\n",
     "    QuantumRandomAccessOptimizer,\n",
@@ -447,7 +444,7 @@
    "source": [
     "## Solve the problem exactly using the `CplexOptimizer`\n",
     "\n",
-    "To evaluate the performance of QRAO in approximating the optimal solution, we can use CPLEX to solve for the exact optimal solution as follows:"
+    "To evaluate the performance of QRAO in approximating the optimal solution, we can use CPLEX, an exact classical optimizer, to solve for the exact optimal solution as follows:"
    ]
   },
   {
@@ -469,6 +466,9 @@
     }
    ],
    "source": [
+    "# pylint: disable=wrong-import-order\n",
+    "from qiskit_optimization.algorithms import CplexOptimizer\n",
+    "\n",
     "cplex_optimizer = CplexOptimizer()\n",
     "cplex_results = cplex_optimizer.solve(problem)\n",
     "exact_fval = cplex_results.fval\n",