Improve README.md

Author: FBumann

README.md

@@ -4,7 +4,9 @@
 
 [![PyPI version](https://badge.fury.io/py/xarray_plotly.svg)](https://badge.fury.io/py/xarray_plotly)
 [![Python](https://img.shields.io/pypi/pyversions/xarray_plotly.svg)](https://pypi.org/project/xarray_plotly/)
+[![CI](https://github.com/FBumann/xarray_plotly/actions/workflows/ci.yml/badge.svg)](https://github.com/FBumann/xarray_plotly/actions)
 [![Docs](https://img.shields.io/badge/docs-fbumann.github.io-blue)](https://fbumann.github.io/xarray_plotly/)
+[![License: MIT](https://img.shields.io/badge/License-MIT-yellow.svg)](https://opensource.org/licenses/MIT)
 
 ## Installation
 
@@ -34,6 +36,8 @@ from xarray_plotly import xpx
 fig = xpx(da).line()
 ```
 
+**Why `xpx()`?** The accessor (`da.plotly`) works but IDEs can't provide code completion for it. This is because xarray accessors are registered dynamically at runtime, making them invisible to static type checkers. The `xpx()` function provides the same functionality with full IDE support. This limitation could only be solved by xarray itself, if at all — it may be a fundamental Python limitation.
+
 ## Documentation
 
 Full documentation: [https://fbumann.github.io/xarray_plotly](https://fbumann.github.io/xarray_plotly)