Document optional django install

Author: rlskoeser

README.md

@@ -43,6 +43,14 @@ Use the `@name` notation to specify the branch or tag; e.g., to install developm
 pip install git+https://github.com/dh-tech/undate-python@develop#egg=undate
 ```
 
+### Optional Django Support (PRELIMINARY / IN PROGRESS)
+
+To install with optional Django integration field support:
+```console
+pip install undate[django]
+```
+
+
 ## Example Usage
 
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