update readme

Author: adorton-adobe

README.md

@@ -3,12 +3,25 @@
 This is a Python client for the User Management API from Adobe, aka the
 [UMAPI](https://www.adobe.io/products/usermanagement/docs/gettingstarted.html).
 
-The User Management API is an Adobe-hosted network service 
-which provides Adobe Enterprise customers the ability to manage their users.  This
-client makes it easy to access the UMAPI from a local Python application.
+The User Management API is an Adobe-hosted network service which provides Adobe
+Enterprise customers the ability to manage their users. This client makes it
+easy to access the UMAPI from a local Python application.
+
+See the [user guide](https://adobe-apiplatform.github.io/umapi-client.py/) for
+more information.
 
 This client is open source, maintained by Adobe, and distributed under the terms
-of the OSI-approved MIT license.  Copyright (c) 2016-2021 Adobe Inc.
+of the OSI-approved MIT license. Copyright (c) 2016-2023 Adobe Inc.
+
+# Compatibility
+
+The `3.x` release branch is actively maintained. New users of the UMAPI client
+should use the latest 3.x release. The `2.x` branch is still supported, but new
+2.x releases will only contain bug fixes. New features will only be developed
+for 3.x.
+
+Pull requests for 3.x should be made against the `v3` branch (the default
+branch). Anything related to 2.x bugfixes should target `v2`.
 
 # Installation
 
@@ -30,8 +43,8 @@ $ poetry add umapi-client
 
 # Building
 
-[Poetry](https://python-poetry.org/) is required to build the package. Follow the instructions documented on
-Poetry's website to install it on your system.
+[Poetry](https://python-poetry.org/) is required to build the package. Follow
+the instructions documented on Poetry's website to install it on your system.
 
 1. Clone this repository
    ```
@@ -44,17 +57,18 @@ Poetry's website to install it on your system.
    $ poetry install
    ```
 
-3. The `build` command will create a source package (`.tar.gz`) and a wheel file (`.whl`) in the `dist` directory.
+3. The `build` command will create a source package (`.tar.gz`) and a wheel file
+   (`.whl`) in the `dist` directory.
+
    ```
    $ poetry build
    $ ls dist
-   umapi-client-2.18.tar.gz  umapi_client-2.18-py3-none-any.whl
+   umapi-client-3.0.tar.gz  umapi_client-3.0-py3-none-any.whl
    ```
 
 4. Some of the packages required by this module use encryption, and so may
-   require you to do local builds of modules that use SSL.  Typically, this
-   will require you to have a python installed that supports compiling
-   extensions.
+   require you to do local builds of modules that use SSL. Typically, this will
+   require you to have a python installed that supports compiling extensions.
 
 5. Run tests with `pytest`.
    ```
@@ -70,4 +84,5 @@ whose sources are in the `docs` directory of this repository.
 
 # License
 
-This project is licensed under the MIT License. See [LICENSE](LICENSE) for more information.
+This project is licensed under the MIT License. See [LICENSE](LICENSE) for more
+information.