fix convert to pdf

docs/exercises/05_classification.ipynb

@@ -261,7 +261,7 @@
     "\n",
     "We are using the package scikit-learn in order to implement such a classification. Scikit-learn is a widely-used Python library for machine learning and data analysis. It provides a wide range of tools for data preprocessing, model selection, and evaluation. Its user-friendly interface and extensive documentation make it a popular choice for researchers, data analysts, and machine learning practitioners.\n",
     "\n",
-    "![scikit-learn logo](https://scikit-learn.org/stable/_static/scikit-learn-logo-small.png)"
+    "<img src=\"https://scikit-learn.org/stable/_static/scikit-learn-logo-small.png\" alt=\"scikit-learn logo\">"
    ]
   },
   {