add missing images

docs/pangeo/dask_introduction.ipynb

@@ -159,15 +159,16 @@
     "\n",
     "When we use chunks with `Xarray`, the real computation is only done when needed or asked for, usually when invoking `compute()` or `load()` functions. Dask generates a **task graph** describing the computations to be done. When using [Dask Distributed](https://distributed.dask.org/en/stable/) a **Scheduler** distributes these tasks across several **Workers**.\n",
     "\n",
-    "![Xarray with dask](../figures/dask-xarray-explained.png)"
+    "![Xarray with dask](../images/dask-xarray-explained.png)"
    ]
   },
   {
    "cell_type": "markdown",
-   "id": "11377e82-113a-4260-8bc6-cc6973a6bab0",
+   "id": "c3e0fa68-3d13-4caa-82c8-a075319e1d56",
    "metadata": {},
    "source": [
-    "#### What is a Dask Distributed cluster ?\n",
+    "#### What is a Dask Distributed cluster?\n",
+    "\n",
     "\n",
     "A Dask Distributed cluster is made of two main components:\n",
     "\n",
@@ -182,7 +183,9 @@
   {
    "cell_type": "markdown",
    "id": "019f6d9c-5927-4d53-9125-432cfe42fef9",
-   "metadata": {},
+   "metadata": {
+    "jp-MarkdownHeadingCollapsed": true
+   },
    "source": [
     "#### Where can we deploy a Dask distributed cluster?\n",
     "\n",