chore: further document the custom docset feature

README.md

@@ -9,3 +9,39 @@
 ## Notes
 
 Due to licensing the distribution on macOS is explicitly forbidden.
+
+## Use with custom docsets
+
+In addition to the list of docsets [published by Dash][official], this plugin
+supports loading custom docsets. You can see [this page][generating] for
+official documentation on how to create a docset. For example, you can use
+[doc2dash][] to create a docset for a Python project with Sphinx documentation:
+
+``` sh
+# Install doc2dash
+pip install doc2dash
+# or
+uv tool install doc2dash
+
+# Build HTML docs according to your project's documentation. For example:
+sphinx-build docs docs/_html
+
+# Use doc2dash to convert to a Dash docset:
+doc2dash docs/_html
+# This should create a directory named $SOMETHING.docset.
+
+# Copy an icon (a 128x128 png file is ideal) into the directory:
+cp icon.png $SOMETHING.docset/icon.png
+
+# The resulting docset directory can be copied to your albert custom_docsets dir
+mkdir -p ~/.local/share/albert/docs/custom_docsets
+cp $SOMETHING.docset ~/.local/share/albert/docs/custom_docsets/
+```
+
+Finally, activate Albert and restart it. On relaunch, Albert will discover the
+custom docset and you should be able to search its headings and open it in your
+web browser.
+
+[official]: https://kapeli.com/dash#docsets
+[generating]: https://kapeli.com/docsets
+[doc2dash]: https://github.com/hynek/doc2dash