Update README

Author: ellieyhcheng

README.md

@@ -238,4 +238,18 @@ def function_name(parameters):
 ### Variable References
 
 - `<variable_name>` - Reference existing Python variables
-- `<:new_variable>` - Create new variables
+- `<:new_variable>` - Create new variables
+
+# Paper & Citation
+
+Read more about shared program state in our [paper](https://arxiv.org/abs/2512.14805).
+
+Please cite Nightjar as follows:
+```
+@article{cheng2025sharing,
+    title     = {Sharing State Between Prompts and Programs},
+    author    = {Cheng, Ellie Y. and Weber, Logan and Jin, Tian and Carbin, Michael},
+    journal   = {arXiv preprint arXiv:2512.14805},
+    year      = {2025},
+}
+```

src/nightjarpy/utils/cache.py

@@ -15,6 +15,7 @@
 logger = logging.getLogger(__name__)
 
 
+# From https://github.com/stanfordnlp/dspy/blob/main/dspy/clients/cache.py
 class Cache:
     """
     `Cache` provides 2 levels of caching (in the given order):