Update README to describe mesa_models and experimental feature

Author: rht

README.md

@@ -2,6 +2,17 @@
 
 This repository contains examples that work with Mesa and illustrate different features of Mesa.
 
-To contribute to this repository, see `CONTRIBUTING.rst`_
+To contribute to this repository, see [CONTRIBUTING.rst](https://github.com/projectmesa/mesa-examples/blob/main/CONTRIBUTING.rst).
 
-.. _`CONTRIBUTING.rst` : https://github.com/projectmesa/mesa-examples/blob/main/CONTRIBUTING.rst
+This repo also contains a package that readily lets you import and run some of the examples:
+```console
+$ # This will install the "mesa_models" package
+$ pip install git+https://github.com/projectmesa/mesa-examples
+```
+```python
+from mesa_models.boltzmann_wealth_model.model import BoltzmannWealthModel
+```
+You can see the available models at [setup.cfg](https://github.com/projectmesa/mesa-examples/blob/main/setup.cfg).
+
+The package also contains experimental code, which will be in the main Mesa package once they have stabilized.
+You can see an example of the `JupyterViz` function in the experimental boltzmann wealth model's [app.py](https://github.com/projectmesa/mesa-examples/blob/main/examples/boltzmann_wealth_model_experimental/app.py).