try to fix thumbnails

Author: ammedd

docs/user-guide/assignments/Code_of_conduct.ipynb

@@ -4,7 +4,7 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "## CODE OF CONDUCT 2025\n",
+    "## Code of conduct\n",
     "_As used during the Dynamical Oceanography 2024/25 course at Utrecht University_"
    ]
   },
@@ -85,6 +85,13 @@
     "\n",
     "The course coordinator reserves the right to refuse admission to anyone violating these policies, and/or take further action including reporting to the responsible figure for academic integrity at the department.\n"
    ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "[Thumbnail image](_images/freepik_code_of_conduct.jpg)"
+   ]
   }
  ],
  "metadata": {

docs/user-guide/assignments/Sail_the_ship.ipynb

@@ -177,6 +177,13 @@
     "![Our ocean provides](https://seewhatgrows.org/wp-content/uploads/2019/06/our-ocean.jpg)\n",
     "![10 ways to help our ocean](https://oceanservice.noaa.gov/ocean/help-ocean.jpg)"
    ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "[Thumbnail image](_images/freepik_research_vessel.jpg)"
+   ]
   }
  ],
  "metadata": {