small edits

module2/exo1/toy_notebook_en.ipynb

@@ -4,7 +4,13 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "#  On the computation of $\\pi$\n",
+    "#  On the computation of $\\pi$"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
     "##  Asking the maths library\n",
     "\n",
     "My computer tells me that $\\pi$ is *approximatively*"
@@ -32,8 +38,8 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "## Buffon’s needle\n",
-    "Applying the method of [Buffon’s needle](https://en.wikipedia.org/wiki/Buffon%27s_needle_problem), we get the __approximation__"
+    "## Buffon's needle\n",
+    "Applying the method of [Buffon's needle](https://en.wikipedia.org/wiki/Buffon%27s_needle_problem), we get the __approximation__"
    ]
   },
   {