add cbar example to notebook

Author: nvaytet

docs/user-guide/imshow.ipynb

@@ -19,10 +19,18 @@
     "import numpy as np"
    ]
   },
+  {
+   "cell_type": "markdown",
+   "id": "2",
+   "metadata": {},
+   "source": [
+    "## Basic imshow"
+   ]
+  },
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "2",
+   "id": "3",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -34,6 +42,29 @@
     "\n",
     "fig"
    ]
+  },
+  {
+   "cell_type": "markdown",
+   "id": "4",
+   "metadata": {},
+   "source": [
+    "## With a colorbar"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "5",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "fig, ax = plt.subplots()\n",
+    "\n",
+    "im = ax.imshow(np.random.random((20, 20)))\n",
+    "fig.colorbar(im)\n",
+    "\n",
+    "fig"
+   ]
   }
  ],
  "metadata": {

src/matplotgl/colorbar.py

@@ -11,7 +11,7 @@
 
 
 class Colorbar:
-    def __init__(self, widget, mappable, height: int | float):
+    def __init__(self, widget, mappable, height: float):
         self._mappable = mappable
         self._height = height
         self._widget = widget