Run black on all the notebooks

- we use black's default settings
- some cells are NOT kept in black's format to:
  - increase readability
  - or show Python's flexibility with regard to style

01_scientific_stack/00_content_numpy.ipynb

@@ -282,10 +282,12 @@
     }
    ],
    "source": [
-    "m1 = np.array([\n",
-    "    [1, 2, 3, 4, 5],\n",
-    "    [6, 7, 8, 9, 10],\n",
-    "])\n",
+    "m1 = np.array(\n",
+    "    [\n",
+    "        [1, 2, 3, 4, 5],\n",
+    "        [6, 7, 8, 9, 10],\n",
+    "    ]\n",
+    ")\n",
     "\n",
     "m1"
    ]