Update README with development pause notice

Author: raquentin

README.md

@@ -2,6 +2,9 @@
 
 Punt Engine is an open-source FPGA-accelerated high-frequency trading engine. See https://punt-engine.com for full documentation.
 
+> [!IMPORTANT]  
+> development paused, resuming dec 2025
+
 ## Components
 
 ### Pipebomb
@@ -18,3 +21,4 @@ Learn more by reading the source or [the docs](https://punt-engine.com/notes/the
 ## Contributing
 
 Most contributors are welcome. Begin by reading through our [docs](https://punt-engine.com) and looking through [open issues tagged "help wanted"](https://github.com/raquentin/punt-engine/issues?q=is%3Aissue+is%3Aopen+label%3A%22help+wanted%22).
+