document which stages use synthesis methods

docs/transpile/transpiler-plugins.ipynb

@@ -197,6 +197,8 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
+    "Unitary synthesis is used in the `init`, `translation`, and `optimization` stages of the staged pass manager returned by [`generate_preset_pass_manager`](/api/qiskit/transpiler_preset#generate_preset_pass_manager) or used in [`transpile`](/api/qiskit/compiler#qiskit.compiler.transpile).\n",
+    "\n",
     "Use the `unitary_synthesis_plugin_config` argument, a free-form dictionary, to pass options for the unitary synthesis method. The documentation of the synthesis method should explain the options it supports. See [this list](/api/qiskit/transpiler_synthesis_plugins#unitary-synthesis-plugins-2) for links to the documentation of the built-in unitary synthesis plugins."
    ]
   },
@@ -231,7 +233,9 @@
     "[LinearFunction](/api/qiskit/qiskit.circuit.library.LinearFunction#linearfunction) objects. The names of the keyword arguments correspond to the \n",
     "[`name`](/api/qiskit/qiskit.circuit.Operation#name) attribute of the [Operation](/api/qiskit/qiskit.circuit.Operation) class representing the type of object being synthesized.\n",
     "For each high-level object, the list of given plugins are tried in sequence until one of them\n",
-    "succeeds (in the example above, each list only contains a single plugin). In addition to specifying\n",
+    "succeeds (in the example above, each list only contains a single plugin).\n",
+    "\n",
+    "In addition to specifying\n",
     "a plugin by its name, you can instead pass a `(name, options)` tuple, where the second element of the tuple is a dictionary containing options for the plugin. The documentation of the synthesis method should explain the options it supports. See [this list](/api/qiskit/transpiler_synthesis_plugins#high-level-synthesis-plugins-2) for links to the documentation of the built-in high-level synthesis plugins.\n",
     "\n",
     "Once you have created the `HLSConfig` object, pass it as the\n",
@@ -248,6 +252,13 @@
     "    optimization_level=3, backend=backend, hls_config=hls_config\n",
     ")"
    ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "High-level synthesis is used in the `init`, `translation`, and `optimization` stages of the staged pass manager returned by [`generate_preset_pass_manager`](/api/qiskit/transpiler_preset#generate_preset_pass_manager) or used in [`transpile`](/api/qiskit/compiler#qiskit.compiler.transpile)."
+   ]
   }
  ],
  "metadata": {