include napari option in install instructions

README.md

@@ -26,6 +26,15 @@ Then install the `movement` package:
 pip install movement
 ```
 
+If you want to use the graphical user interface (GUI), which is provided via
+a [`napari`](https://napari.org/) plugin, run these commands instead:
+
+```
+conda create -n movement-env -c conda-forge python=3.11 pytables napari pyqt
+conda activate movement-env
+pip install movement[napari]
+```
+
 > [!Note]
 > Read the [documentation](https://movement.neuroinformatics.dev) for more information, including [full installation instructions](https://movement.neuroinformatics.dev/getting_started/installation.html) and [examples](https://movement.neuroinformatics.dev/examples/index.html).
 

docs/source/getting_started/installation.md

@@ -19,14 +19,24 @@ conda create -n movement-env -c conda-forge python=3.11 pytables
 conda activate movement-env
 ```
 
+If you want to use the graphical user interface (GUI), which is provided via
+a [`napari`](napari:) plugin, you'd also need to include `napari` and `pyqt`
+in the environment:
+
+```sh
+conda create -n movement-env -c conda-forge python=3.11 pytables napari pyqt
+conda activate movement-env
+```
+
+
 ## Install the package
 
 Then install the `movement` package as described below.
 
 ::::{tab-set}
 
-:::{tab-item} Users
-To get the latest release from PyPI:
+:::{tab-item} Without the GUI
+To install the core package from PyPI:
 
 ```sh
 pip install movement
@@ -39,7 +49,21 @@ pip install --upgrade movement
 ```
 :::
 
-:::{tab-item} Developers
+:::{tab-item} With the GUI
+To install the package including the GUI (napari plugin) from PyPI:
+
+```sh
+pip install movement[napari]
+```
+If you have an older version of `movement` installed in the same environment,
+you can update to the latest version with:
+
+```sh
+pip install --upgrade movement[napari]
+```
+:::
+
+:::{tab-item} For developers
 To get the latest development version, clone the
 [GitHub repository](movement-github:)
 and then run from inside the repository:
@@ -66,3 +90,12 @@ movement info
 
 You should see a printout including the version numbers of `movement`
 and some of its dependencies.
+
+To test the GUI installation, you can run:
+
+```sh
+napari -w movement
+```
+
+This should open a new `napari` window with the `movement` plugin loaded
+on the right side.