expand on usage on homepage

Author: ianhi

docs/index.rst

@@ -17,8 +17,17 @@ Installation
 Usage
 ^^^^^
 
+- Left-click to place a point
+- Right click to remove the nearest point
+- Left click on legend to change classes
+- Get positions with ``.get_positions()``
+
 .. code-block:: python
 
+   import numpy as np
+   import matplotlib.pyplot as plt
+   from mpl_point_clicker import clicker
+
    fig, ax = plt.subplots(constrained_layout=True)
    image = np.random.rand(512, 512)
    ax.imshow(image, cmap="gray")
@@ -28,7 +37,27 @@ Usage
       markers=["o", "x", "*"]
    )
 
-You can then access the positions via ``klicker.get_positions``.
+
+You can also add scroll to zoom and middle-click and drag to pan with tools from
+`mpl-interactions <https://mpl-interactions.readthedocs.io/en/stable/examples/zoom-factory.html>`_
+
+.. code-block:: python
+
+   from mpl_interactions import zoom_factory, panhandler
+
+   fig, ax = plt.subplots(constrained_layout=True)
+   image = np.random.rand(512, 512)
+   ax.imshow(image, cmap="gray")
+
+   # add zooming and middle click to pan
+   zoom_factory(ax)
+   ph = panhandler(fig, button=2)
+
+   klicker = clicker(
+      ax,
+      ["cell", "pdms", "media"],
+      markers=["o", "x", "*"]
+   )